JP6725766B2 - Narrowband time division duplex frame structure for narrowband communication - Google Patents

Description

CROSS REFERENCE TO RELATED TECHNOLOGY This application is an Indian application No. 201741005220, NARROW BAND TIME-DIVISION DUPLEX FRAME STRUCTURE FOR NARROWBAND COMMUNICATIONS filed on February 15, 2017, and India application No. 201741005360 filed on September 18, 2017, "NARROWBAND TIME-DIVISION DUPLEX FRAME Claim the benefit of US Patent Application No. 15/707,789 entitled "STRUCTURE FOR NARROWBAND COMMUNICATIONS".

The present disclosure relates generally to communication systems, and more particularly to narrowband time division duplex (TDD) frame structures for narrowband communication.

Wireless communication systems are widely deployed to provide various telecommunications services such as telephone, video, data, messaging, and broadcast. A typical wireless communication system may utilize multiple access technologies capable of supporting communication with multiple users by sharing the available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier. There are frequency division multiple access (SC-FDMA) systems and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in various telecommunications standards to provide a common protocol that allows different wireless devices to communicate in cities, countries, regions, and even globally. An exemplary telecommunications standard is 5G New Radio (NR). 5G NR is announced by the 3rd Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g. with the Internet of Things (IoT)), and other requirements. It is part of the continuous evolution of mobile broadband. Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There is a need for further improvement of 5G NR technology. These improvements may also be applicable to other multiple access technologies and telecommunications standards that employ these technologies.

Narrowband communication involves communication with a limited frequency bandwidth compared to the frequency bandwidth used for LTE communication. An example of narrowband communication is narrowband (NB) IoT (NB-IoT) communication, which is limited to a single resource block (RB) of the system bandwidth, eg 180 kHz. Another example of narrowband communication is enhanced machine-type communication (eMTC), which is limited to 6 RBs of system bandwidth, eg 1.08 MHz.

NB-IoT communication and eMTC may reduce device complexity, enable multi-year battery life, and provide deeper coverage to reach difficult locations such as deep inside buildings. The coverage provided by narrowband communications may include reaching difficult locations (eg, smart gas meters located in the basement of a building), thus increasing the probability that one or more transmissions will not be received properly. Therefore, iterative transmissions may be used in narrowband communications to increase the probability that the transmissions will be properly decoded by the receiver device. The TDD frame structure may support repetitive transmission due to the large number of consecutive downlink and/or uplink subframes as compared to the frequency division duplex (FDD) frame structure. .. It is necessary to support the narrow band TDD frame structure for narrow band communication.

The following presents a simplified summary of one or more aspects to enable a basic understanding of such aspects. This summary is not an extensive overview of all possible aspects and is neither intended to identify key or critical elements of all aspects nor to delineate any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

Narrowband communication involves communication with a limited frequency bandwidth compared to the frequency bandwidth used for LTE communication. One example of narrowband communication is NB-IoT communication, which is limited to a single RB as the system bandwidth, for example 180 kHz. Another example of narrowband communication is eMTC, which is limited to 6 RBs of system bandwidth, eg 1.08 MHz.

NB-IoT communication and eMTC may reduce device complexity, enable multi-year battery life, and provide deeper coverage to reach difficult locations such as deep inside buildings. However, the coverage provided by narrowband communication may involve reaching difficult locations (e.g., smart gas meters located in the basement of a building) so that one or more transmissions are not properly decoded by the receiver device. The probability increases. As a result, narrowband communication may include a predetermined number of repetitive transmissions in order to increase the probability that the transmission will be properly decoded by the receiver device. The TDD frame structure may be used by narrowband communication systems, which means that some TDD frame structures may be used for repetitive transmission, compared to the FDD frame structure. This is because it may include a typical uplink subframe and/or downlink subframe. There is a need to support the use of narrowband TDD frame structures for narrowband communication.

This disclosure provides a mechanism for supporting one or more narrowband TDD frame structures for narrowband communication.

In one aspect of the disclosure, methods, computer readable media, and devices are provided. The device may determine a bandwidth for narrowband communication. The device may determine a narrowband TDD frame structure for narrowband communication. In one aspect, the narrowband TDD frame structure comprises two or more consecutive downlink subframes or one or more flexible subframes that can be configured as either downlink or uplink subframes. It may include at least one of them. The apparatus may communicate with the UE using the narrowband TDD frame structure determined for narrowband communication.

In some aspects a device may determine a TDD mode for narrowband communication. The apparatus may also determine a TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In an aspect, at least one common subframe in each narrowband TDD frame structure in the group of narrowband TDD frame structures may be configured as a downlink subframe. The apparatus may also transmit the primary synchronization signal (PSS) using at least one common subframe in the narrowband TDD frame structure determined for narrowband communication.

In some other aspects, the device may determine a TDD mode for narrowband communication. The apparatus may also determine a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. The device may also transmit the PSS using the narrowband TDD frame structure determined for narrowband communication. In an aspect, the set of PSS sequences may be associated with at least one of a TDD mode or a narrowband TDD frame structure determined for narrowband communication.

In some other aspects, an apparatus determines a narrowband communication frame structure comprising a FDD mode or a TDD mode and a particular TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. Good. The apparatus may determine the period associated with the SSS, the subframe number, and the transmission sequence based at least in part on the narrowband TDD frame structure. The device may send the SSS using the narrowband TDD frame structure determined for narrowband communication. In one aspect, the SSS may be transmitted using the same subframe in at most every other frame.

In some other aspects, an apparatus includes a narrowband communication frame structure comprising a FDD frame structure or a TDD frame structure, and a narrowband TDD frame structure structure for narrowband communication from a group of narrowband TDD frame structure structures. May be determined. An apparatus may include one or more narrowband carriers and one or more narrowband carriers for transmitting at least one of BCH or SIB1 based on the narrowband communication frame structure or TDD frame structure configuration. May be determined. The apparatus may transmit the PSS, SSS, and/or at least one of BCH or SIB1 using the narrowband TDD frame structure determined for narrowband communication. In one aspect, the carrier used to transmit the BCH and/or SIB may be different than the carrier used to transmit one or more of the PSS or SSS. In another aspect, the narrowband carrier used to transmit the BCH may be different than the narrowband carrier used to transmit one or more of the PSS or SSS.

In some other aspects, an apparatus may determine a narrowband TDD frame structure for narrowband communication. In an aspect, the narrowband TDD frame structure may include one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes. In some other aspects, an apparatus may send a bitmap associated with a narrowband TDD frame structure to a UE. In one aspect, the bitmap may indicate one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes.

The apparatus may determine a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In one aspect, the narrowband TDD frame structure may include a downlink subframe and a set of two or more special subframes. The apparatus determines a minimum set of narrowband carriers and a subframe on the set of narrowband carriers based at least in part on the downlink subframe and the set of two or more special subframes over which the NRS should be transmitted. The limit set may be determined. The device may transmit the NRS using the narrowband TDD frame structure determined for narrowband communication.

To the accomplishment of the foregoing and related ends, one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of one or more embodiments. However, these features are merely representative of some of the various ways in which principles of various aspects may be employed, and this description includes all such aspects and their equivalents. Let's assume.

It is a figure which shows the example of a wireless communication system and an access network. It is a figure which shows the example of LTE of DL frame structure. It is a figure which shows the example of LTE of the DL channel in a DL frame structure. It is a figure which shows the example of LTE of a UL frame structure. It is a figure which shows the example of LTE of the UL channel in a UL frame structure. It is a figure which shows the example of evolved Node B (eNB) and user equipment (UE) in an access network. FIG. 6 illustrates an exemplary narrowband TDD frame structure according to some aspects of the present disclosure. FIG. 6 is a data flow diagram for narrowband communication using a narrowband TDD frame structure according to certain aspects of the present disclosure. FIG. 6 is a data flow diagram for narrowband communication using a narrowband TDD frame structure according to certain aspects of the present disclosure. FIG. 6 is a data flow diagram for narrowband communication using a narrowband TDD frame structure according to certain aspects of the present disclosure. FIG. 6 is a data flow diagram for narrowband communication using a narrowband TDD frame structure according to certain aspects of the present disclosure. 3 is a flowchart of a method of wireless communication. 3 is a flowchart of a method of wireless communication. 3 is a flowchart of a method of wireless communication. 3 is a flowchart of a method of wireless communication. 3 is a flowchart of a method of wireless communication. FIG. 3 is a conceptual data flow diagram showing the data flow between different means/components in an exemplary device. It is a figure which shows the example of the hardware mounting form of the apparatus which uses a processing system. FIG. 3 is a conceptual data flow diagram showing the data flow between different means/components in an exemplary device. It is a figure which shows the example of the hardware mounting form of the apparatus which uses a processing system. FIG. 3 is a conceptual data flow diagram showing the data flow between different means/components in an exemplary device. It is a figure which shows the example of the hardware mounting form of the apparatus which uses a processing system. FIG. 3 is a conceptual data flow diagram showing the data flow between different means/components in an exemplary device. It is a figure which shows the example of the hardware mounting form of the apparatus which uses a processing system. FIG. 3 is a conceptual data flow diagram showing the data flow between different means/components in an exemplary device. It is a figure which shows the example of the hardware mounting form of the apparatus which uses a processing system. FIG. 6 is a data flow diagram for narrowband communication using a narrowband TDD frame structure according to certain aspects of the present disclosure. 3 is a flowchart of a method of wireless communication. FIG. 3 is a conceptual data flow diagram showing the data flow between different means/components in an exemplary device. It is a figure which shows the example of the hardware mounting form of the apparatus which uses a processing system. 3 is a flowchart of a method of wireless communication.

The form for carrying out the invention described below with reference to the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configuration in which the concepts described herein may be practiced. Not intended. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

In the following, some aspects of telecommunication systems are presented with reference to various devices and methods. These devices and methods are described in the detailed description below, and illustrated in the accompanying drawings by various blocks (collectively referred to as "elements"), components, circuits, processes, algorithms, etc. These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the particular application and design constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a "processing system" that includes one or more processors. Examples of processors are microprocessors, microcontrollers, graphics processing units (GPU), central processing units (CPU), application processors, digital signal processors (DSP), reduced instruction set computing (RISC) processors, system-on-chip. (SoC), baseband processor, field programmable gate array (FPGA), programmable logic device (PLD), state machine, gate logic, discrete hardware circuits, and to perform various functions described throughout this disclosure. There is other suitable hardware configured. One or more processors in the processing system may execute software. Software includes instructions, instruction sets, codes, code segments, program codes, programs, subprograms, software components, applications, software applications, software, regardless of the names of software, firmware, middleware, microcode, hardware description language, etc. It should be broadly construed to mean packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc.

Thus, in one or more exemplary embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on a computer-readable medium or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. A storage media may be any available media that can be accessed by a computer. By way of non-limiting example, such computer readable media include random access memory (RAM), read only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices. , A combination of computer-readable media of the types described above, or any other media usable for storing computer-executable code in the form of instructions or data structures accessible by a computer.

FIG. 1 is a diagram illustrating an example of a wireless communication system and an access network 100. A wireless communication system (also called a wireless wide area network (WWAN)) includes a base station 102, a UE 104, and an Evolved Packet Core (EPC) 160. Base stations 102 may include macro cells (high power cellular base stations) and/or small cells (low power cellular base stations). The macro cell includes a base station. Small cells include femtocells, picocells, and microcells.

A base station 102 (collectively referred to as an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) interfaces with an EPC 160 via a backhaul link 132 (eg, S1 interface). In addition to other functions, the base station 102 can transfer user data, encrypt and decrypt wireless channels, integrity protection, header compression, mobility control functions (eg, handover, dual connectivity), inter-cell interference coordination. , Connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracking , RAN information management (RIM), paging, positioning, and delivery of alert messages may perform one or more of the functions. The base stations 102 may communicate with each other directly on the backhaul link 134 (eg, X2 interface) or indirectly (eg, via EPC 160). The backhaul link 134 may be wired or wireless.

Base station 102 may communicate wirelessly with UE 104. Each base station 102 may provide communication coverage for a respective geographical coverage area 110. There may be overlapping geographical coverage areas 110. For example, the small cell 102′ may have a coverage area 110′ that overlaps the coverage area 110 of one or more macro base stations 102. Networks that include both small cells and macro cells are sometimes known as heterogeneous networks. Heterogeneous networks may also include Home Evolved Node Bs (eNBs) (HeNBs) that may serve limited groups known as Limited Subscriber Groups (CSGs). The communication link 120 between the base station 102 and the UE 104 is an uplink transmission from the UE 104 to the base station 102 (also called the reverse link) and/or a down link from the base station 102 to the UE 104 (also called the forward link). May include link transmission. Communication link 120 may use multiple input multiple output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. Communication links may be through one or more carriers. Base stations 102/UE104 are allocated in carrier aggregation up to a total of YxMHz (x component carriers) used for transmission in each direction, up to YMHz per carrier (e.g. 5, 10, 15, 20, 100MHz). May use a spectrum with a bandwidth of. The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to the downlink and uplink (eg, downlink may have more or less carriers allocated than uplink). Component carriers may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be called a primary cell (PCell), and the secondary component carrier may be called a secondary cell (SCell).

Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 192. D2D communication link 192 may use the DL/UL WWAN spectrum. The D2D communication link 192 includes one or more physical sidelink broadcast channels (PSBCH), physical sidelink discovery channel (PSDCH), physical sidelink shared channel (PSSCH), and physical sidelink control channel (PSCCH). May use sidelink channels. The D2D communication may be through various wireless D2D communication systems such as FlashLinQ, WiMedia, Bluetooth (registered trademark), ZigBee, Wi-Fi based on IEEE 802.11 standard, LTE, or NR.

The wireless communication system may further include a Wi-Fi access point (AP) 150 in communication with a Wi-Fi station (STA) 152 via a communication link 154 in the 5 GHz unlicensed frequency spectrum. When communicating in the unlicensed frequency spectrum, the STA 152/AP 150 may perform a clear channel assessment (CCA) prior to communicating to determine if the channel is available.

Small cell 102′ may operate in the licensed frequency spectrum and/or the unlicensed frequency spectrum. When operating in the unlicensed frequency spectrum, the small cell 102' may utilize NR and use the same 5 GHz unlicensed frequency spectrum used by the Wi-Fi AP 150. Small cells 102' that utilize NR in the unlicensed frequency spectrum may extend coverage to the access network and/or increase capacity of the access network.

The gNodeB (gNB) 180 may operate at millimeter wave (mmW) frequencies and/or near mmW frequencies (near mmW frequency) when communicating with the UE 104. When the gNB180 operates at the mmW frequency or quasi-mmW frequency, the gNB180 is sometimes referred to as an mmW base station. Extreme frequency (EHF) is part of RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and wavelengths between 1 millimeter and 10 millimeters. Radio waves in this band are sometimes called millimeter waves. Quasi-mmW has a wavelength of 100 millimeters and can span frequencies up to 3 GHz. The very high frequency (SHF) band, also called centimeter wave, spans between 3 GHz and 30 GHz. Communications using the mmW/quasi-mmW radio frequency band have extremely high path loss and short range. mmW base station 180 may utilize beamforming 184 for UE 104 to compensate for extremely high path loss and short distances.

The EPC 160 includes a Mobility Management Entity (MME) 162, another MME 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a packet data network (BM-SC). PDN) gateway 172. The MME 162 may be in communication with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Generally, the MME 162 provides bearers and connection management. All user internet protocol (IP) packets are forwarded through the serving gateway 166, which is itself connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation as well as other functions. The PDN gateway 172 and BM-SC 170 are connected to the IP service 176. IP services 176 may include the Internet, intranets, IP multimedia subsystems (IMSs), PS streaming services, and/or other IP services. The BM-SC170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC170 may act as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within the Public Land Mobile Network (PLMN), and schedule MBMS transmissions. It may be used to The MBMS gateway 168 may be used to deliver MBMS traffic to base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area that broadcasts specific services, session management (start/stop) and eMBMS. It may be responsible for collecting the relevant billing information.

A base station can be a gNB, Node B, evolved Node B (eNB), access point, transceiver base station, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), or other It may also be called in any suitable term. Base station 102 provides UE 104 with an access point to EPC 160. Examples of UE104 include mobile phones, smartphones, session initiation protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 player), camera, game console, tablet, smart device, wearable device, vehicle, electricity meter, gas pump, toaster, or any other similar functional device. A portion of UE 104 may be referred to as an IoT device (eg, parking meter, gas pump, toaster, vehicle, etc.). UE 104 is a station, mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless. It may also be referred to as a terminal, remote terminal, handset, user agent, mobile client, client, or any other suitable term.

Referring back to FIG. 1, in some aspects a base station 102, 180, and/or a UE 104 may be provided for narrowband communication, eg, as described in connection with any of FIGS. 4-25. It may be configured to support one or more narrowband TDD frame structures (198).

FIG. 2A is a diagram 200 showing an example of a DL frame structure in LTE. FIG. 2B is a diagram 230 illustrating an example of channels in a DL frame structure in LTE. FIG. 2C is a diagram 250 illustrating an example of a UL frame structure in LTE. FIG. 2D is a diagram 280 illustrating an example of channels within a UL frame structure in LTE. Other wireless communication technologies may have different frame structures and/or different channels. In LTE, a frame (10 ms) may be divided into 10 equally sized subframes. Each subframe may include two consecutive time slots. A resource grid may be used to represent two time slots, where each time slot includes one or more simultaneous resource blocks (RBs) (also called physical RBs (PRBs)). The resource grid is divided into multiple resource elements (RE). In LTE, in the case of normal cyclic prefix, RB includes 12 consecutive subcarriers in the frequency domain for a total of 84 REs, and 7 consecutive symbols in the time domain (OFDM symbol in the case of DL, In case of UL, SC-FDMA symbol) is included. In the case of the extended cyclic prefix, RB includes 12 consecutive subcarriers in the frequency domain and 6 consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

As shown in FIG. 2A, some of the REs carry DL reference (pilot) signals (DL-RS) for channel estimation at the UE. DL-RS may include a cell-specific reference signal (sometimes referred to as a common RS) (CRS), a UE-specific reference signal (UE-RS), and a channel state information reference signal (CSI-RS). .. Figure 2A is a CRS for _{(respectively, R 0, R 1, R} 2, and indicated as R ₃₎ antenna ports 0, 1, 2, and 3, (indicated as R ₅₎ Antenna Port 5 shows UE-RS for 5 and CSI-RS for antenna port 15 (denoted as R). FIG. 2B shows an example of various channels within a DL subframe of a frame. The Physical Control Format Indicator Channel (PCFICH) is in symbol 0 of slot 0 and the Physical Downlink Control Channel (PDCCH) occupies one symbol, two symbols, or three symbols. It carries a Control Format Indicator (CFI) that indicates (FIG. 2B shows a PDCCH occupying 3 symbols). The PDCCH carries downlink control information (DCI) in one or more control channel elements (CCEs), each CCE contains nine RE groups (REGs), and each REG has four consecutive OFDM symbols. Including RE. The UE may be configured with a UE-specific enhanced PDCCH (ePDCCH) that also carries DCI. The ePDCCH may have 2, 4, or 8 RB pairs (FIG. 2B shows two RB pairs, each subset containing one RB pair). The physical hybrid automatic repeat request (ARQ) (HARQ) indicator channel (PHICH) is also in symbol 0 of slot 0, and HARQ acknowledgment (ACK)/negative acknowledgment (NACK) feedback based on the physical uplink shared channel (PUSCH). Carry a HARQ indicator (HI). The Primary Synchronization Channel (PSCH) is in symbol 6 of slot 0 in subframes 0 and 5 of the frame and carries the PSS used by the UE to determine subframe timing and physical layer identification information. .. The secondary synchronization channel (SSCH) is in symbol 5 of slot 0 in subframes 0 and 5 of the frame and carries the SSS used by the UE to determine the physical layer cell identity group number. The UE can determine the physical cell identifier (PCI) based on the physical layer identification information and the physical layer cell identification information group number. Based on PCI, the UE can determine the location of DL-RS described above. The physical broadcast channel (PBCH) is in symbols 0, 1, 2, 3 of slot 1 of subframe 0 of the frame and carries the master information block (MIB). The MIB provides the number of RBs in the DL system bandwidth, PHICH configuration, and system frame number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not transmitted over the PBCH, such as the System Information Block (SIB), and paging messages.

As shown in FIG. 2C, some of the REs carry demodulation reference signals (DM-RS) for channel estimation at the eNB. The UE may further transmit a sounding reference signal (SRS) in the last symbol of the subframe. The SRS may have a comb structure and the UE may send the SRS on one of the combs. SRS may be used by the eNB for channel quality estimation to enable frequency dependent scheduling on UL. FIG. 2D shows an example of various channels within a UL subframe of a frame. The Physical Random Access Channel (PRACH) may be in one or more subframes in the frame based on the PRACH configuration. The PRACH may include 6 consecutive RB pairs in a subframe. PRACH allows the UE to perform initial system access and achieve UL synchronization. The Physical Uplink Control Channel (PUCCH) may be located at the edge of UL system bandwidth. The PUCCH carries uplink control information (UCI) such as scheduling request, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and HARQ ACK/NACK feedback. The PUSCH may also be used to carry data and carry buffer status reports (BSR), power headroom reports (PHR), and/or UCI.

FIG. 3 is a block diagram of an eNB 310 communicating with a UE 350 in an access network. In DL, IP packets from EPC 160 may be provided to controller/processor 375. Controller/processor 375 implements Layer 3 and Layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor 375 is capable of broadcasting system information (e.g. MIB, SIB), RRC connection control (e.g. RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), Radio Access Technology (RAT) RRC layer functionality associated with mobility and measurement configuration for UE measurement reporting and PDCP layer associated with header compression/decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functionality Functions and transfer of upper layer packet data units (PDUs), error correction via ARQ, concatenation of RLC service data units (SDUs), segmentation and reassembly, resegmentation of RLC data PDUs and alignment of RLC data PDUs. RLC layer functions associated with switching, mapping between logical channels and transport channels, MAC SDU multiplexing on transport blocks (TB), MAC SDU demultiplexing from TB, scheduling information reporting, It provides error correction via HARQ, priority handling, and MAC layer functions associated with logical channel prioritization.

Transmit (TX) processor 316 and receive (RX) processor 370 implement Layer 1 functions associated with various signal processing functions. Layer 1, which includes the physical (PHY) layer, includes error detection on the transport channel, forward error correction (FEC) coding/decoding on the transport channel, interleaving, rate matching, and mapping on the physical channel. , May include physical channel modulation/demodulation and MIMO antenna processing. TX processor 316 is based on various modulation schemes (e.g., 2 phase shift keying (BPSK), 4 phase shift keying (QPSK), M phase shift keying (M-PSK), M quadrature amplitude modulation (M-QAM)). Handles mapping to signal constellation. The coded and modulated symbols may then be split into parallel streams. Each stream is then mapped to OFDM subcarriers and multiplexed with a reference signal (e.g., pilot) in the time domain and/or frequency domain to generate a physical channel that carries the time domain OFDM symbol stream, and then , May be combined together using the Inverse Fast Fourier Transform (IFFT). The OFDM stream is spatially precoded to generate multiple spatial streams. The channel estimates from channel estimator 374 may be used to determine coding and modulation schemes and for spatial processing. Channel estimates may be derived from reference signals and/or channel state feedback transmitted by UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a respective spatial stream for transmission.

At UE 350, each receiver 354RX receives a signal through a respective antenna 352 of the receiver. Each receiver 354RX recovers the information modulated on the RF carrier and provides that information to the receive (RX) processor 356. TX processor 368 and RX processor 356 implement layer 1 functions associated with various signal processing functions. RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for UE 350. If multiple spatial streams are destined for UE 350, the multiple spatial streams may be combined by RX processor 356 into a single OFDM symbol stream. RX processor 356 then transforms the OFDMA symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols and reference signals on each subcarrier are recovered and demodulated by determining the constellation points of the signals most likely to be transmitted by the eNB 310. These soft decisions may be based on the channel estimates calculated by channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted by eNB 310 on the physical channel. The data and control signals are then provided to a controller/processor 359 that implements Layer 3 and Layer 2 functionality.

Controller/processor 359 may be associated with memory 360 that stores program code and data. Memory 360 may be referred to as a computer-readable medium. In UL, controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from EPC160. And do. Controller/processor 359 is also responsible for error detection supporting HARQ operation using ACK and/or NACK protocols.

Similar to the functionality described for DL transmission by the eNB310, the controller/processor 359 includes RRC layer functionality associated with system information (e.g., MIB, SIB) collection, RRC connection, and measurement reporting, and header compression/decompression and security. PDCP layer functions associated with (encryption, decryption, integrity protection, integrity verification) and upper layer PDU transfer, error correction through ARQ, RLC SDU concatenation, segmentation and reassembly, and RLC data PDU reassembly. RLC layer functions associated with segmentation and RLC data PDU reordering and mapping between logical and transport channels, MAC SDU multiplexing on TB, MAC SDU demultiplexing from TB, scheduling It provides information reporting, error correction through HARQ, priority handling, and MAC layer functions associated with logical channel prioritization.

From the reference signal or feedback sent by the eNB310, the channel estimate derived by the channel estimator 358 is used by the TX processor 368 to select the appropriate coding and modulation scheme and to facilitate spatial processing. May be used. The spatial streams generated by TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.

UL transmissions are processed in the eNB 310 in a manner similar to that described for the receiver function in the UE 350. Each receiver 318RX receives a signal through a respective antenna 320 of the receiver. Each receiver 318RX recovers the information modulated on the RF carrier and provides that information to the RX processor 370.

The controller/processor 375 may be associated with a memory 376 that stores program code and data. Memory 376 may be referred to as a computer-readable medium. At UL, controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from UE350. And do. IP packets from controller/processor 375 may be provided to EPC 160. Controller/processor 375 is also responsible for error detection supporting HARQ operation using ACK and/or NACK protocols.

Narrowband communication involves communication with a limited frequency bandwidth compared to the frequency bandwidth used for LTE communication. One example of narrowband communication is NB-IoT communication, which is limited to a single RB as the system bandwidth, for example 180 kHz. Another example of narrowband communication is eMTC, which is limited to 6 RBs of system bandwidth, eg 1.08 MHz.

NB-IoT communication and eMTC may reduce device complexity, enable multi-year battery life, and provide deeper coverage to reach difficult locations such as deep inside buildings. However, the coverage provided by narrowband communication may involve reaching difficult locations (e.g., smart gas meters located in the basement of a building) so that one or more transmissions are not properly decoded by the receiver device. The probability increases. As a result, narrowband communication may include a predetermined number of repetitive transmissions in order to increase the probability that the transmission will be properly decoded by the receiver device. The TDD frame structure may be used by narrowband communication systems, which means that some TDD frame structures may be used for repetitive transmission, compared to the FDD frame structure. This is because it may include a typical uplink subframe and/or downlink subframe. There is a need to support the use of narrowband TDD frame structures for narrowband communication.

The present disclosure provides a mechanism for supporting one or more narrowband TDD frame structures for narrowband communication, as described below with reference to FIGS. 5A-5D.

FIG. 4 is a diagram illustrating a narrowband TDD frame structure 400 that may be used for narrowband communication in accordance with certain aspects of the present disclosure. In an aspect, the narrowband TDD frame structure 400 used for narrowband communication may be determined from the group of narrowband TDD frame structures (eg, Configuration 0 to Configuration n) listed in Table 410. In some aspects a base station may determine a narrowband TDD frame structure based on higher layer signaling (eg, RRC messaging) received from a network. In some other aspects, a base station may determine a narrowband TDD frame structure based on channel conditions.

In one aspect, the narrowband TDD frame structure 400 may include a 10 ms radio frame that is divided into two half frames, each 5 ms long. The half frame may be further divided into 5 subframes, each 1 ms long. Narrowband TDD frame structure 400 may be any of the narrowband configurations listed in Table 410.

The switching period is to switch between monitoring downlink subframes (eg, for downlink transmissions from base stations) and transmitting transmissions using uplink subframes, and vice versa. To refer to the time used by the UE. Depending on the determined narrowband TDD frame structure 400, the switching period may be 5 ms, 10 ms, or 10 ms or more (eg, 20 ms). In narrowband TDD frame structure 412 with a switching period of 5 ms, special subframes (SSFs) may be placed in both half frames of narrowband TDD frame structure 400. In narrowband TDD frame structure 414 with a switching period of 10 ms, the special subframes may be placed in the first half frame but not in the second half frame. In narrowband TDD frame structure 416 where the switching period is longer than 10 ms, more than the entire frame may be used to perform the switching, so special subframes may not be needed. In narrowband TDD frame structures 412, 414 (e.g. configurations 0, 1, 2, 3, 4, 5, and 6) containing special subframes, subframes 0 and 5 as well as downlink pilots in special subframes Time slots (DwPTS) may be reserved for downlink transmission. Additionally and/or alternatively, in the narrowband TDD frame structure 412, 414 that includes a special subframe, the uplink pilot timeslot (UpPTS) in the special subframe and the subframe immediately following the special subframe are up. It may be reserved for link transmission.

Narrowband TDD frame structure 400 reuses some LTE TDD frame structures (e.g. configurations 0, 1, 2, 3, 4, 5, 6) when operating in in-band mode and/or guard band mode. You may. When operating in stand-alone mode, some subframes in narrowband TDD frame structure 400 may be marked as flexible subframes (e.g., configurations m and n) and the current subframe received from the base station. Depending on the grant, it may be used by the UE as either a downlink subframe or an uplink subframe.

In some aspects a subset of the narrowband TDD configurations listed in table 410 of FIG. 4 may be used to support narrowband communications. For example, configuration 0 may not be suitable for narrowband communication because configuration 0 may not support repetitive transmissions to the UE as it has only two downlink subframes. In some aspects, narrowband communication using a narrowband TDD frame structure may only be supported in inband mode and/or guardband mode (eg, not supported in standalone mode). In some other aspects, narrowband communication using a narrowband TDD frame structure may support in-band mode, guardband mode, and standalone mode.

Multiple narrowband downlink carriers and multiple narrowband uplink carriers may be used to enhance narrowband communication between a base station and a UE. Among other carriers, narrowband anchor carriers may be used to provide synchronization, system information, paging, data, and control for multi-carrier capable UEs. Overhead narrowband system information may be reduced if narrowband anchor carriers are used. For example, synchronization and paging for a cell may not be provided on all narrowband carriers. Narrowband carriers that do not provide synchronization and/or paging are sometimes referred to as narrowband non-anchor carriers. Coordination between base stations for selecting anchor carriers that mitigate interference, and coordination between base stations for transmit power control of non-anchor carriers may provide additional network performance advantages.

Information indicating the determined narrowband TDD frame structure 400 may be obtained using narrowband PSS (NPSS), narrowband SSS (NSSS), narrowband PBCH (NPBCH), and/or SIB (e.g., narrowband anchor carrier). May be transmitted from the base station to the UE.

In in-band and guard-band modes, the narrowband anchor carrier used for narrowband communication (for example, using the narrowband TDD frame structure) is the RB pair for downlink transmission from the base station to the UE. May be placed inside. In some aspects a UE may monitor one RB at any given time. In one example, the SIB and/or NPBCH may reach the UE in the first RB of the RB pair and the NPSS and/or NSSS may reach the UE in the second RB of the pair. In another example, the SIB may reach the UE in the first RB of the RB pair and the NPSS, NSSS, and/or NPBCH may reach the UE in the second RB of the pair. The position of one RB may be determined by the UE based on the position of the other RB in the pair or based on the position of different RBs in different RB pairs (e.g., implicitly derived). May be).

In addition, the UE may send the uplink transmission using the RB pair. In some aspects, the UE determines which of the RB pairs to use for uplink transmission based on signaling received from the base station (e.g., higher layer signaling). May be. In some other aspects, the UE may determine which RB pair to use for uplink transmission based on the type of uplink channel to be transmitted (e.g., PRACH and ACK/NACK). Uses one RB and PUSCH uses the other RB). In some other aspects, the UE may determine which RB pair to use for uplink transmission based on coverage level and/or channel conditions.

FIG. 5A is a diagram illustrating a data flow 500 that may be used for narrowband communication, according to certain aspects of the present disclosure. For example, data flow 500 may be performed by base station 504 and/or UE 506. Base station 504 may correspond to, for example, base stations 102, 180, eNB310, devices 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'. is there. The UE 506 may correspond to the UE 104, 350, 1150, 1350, 1550, 1750, 1950, 2350, for example. Additionally, base station 504 and UE 506 may be configured to communicate using narrowband communication 509 (eg, NB-IoT and/or eMTC). For example, UE 506 may be a NB-IoT device and/or an eMTC device. In FIG. 5A, the optional actions are indicated by dotted lines.

Referring to FIG.5A, the base station 504 may operate in a standalone mode (501) and the base station determines the bandwidth available for LTE communication (e.g., 1.4MHz, 3MHz, 5MHz, 10MHz, 15MHz, 20MHz, A standalone mode bandwidth for narrow band communication 509 (eg, 1.08 MHz or 180 kHz) may be used, different from (eg, 100 MHz).

In some aspects, base station 504 may determine a narrowband TDD frame structure for narrowband communication 509 (503). In one aspect, the narrowband TDD frame structure may be a TDD frame structure that is different than the LTE TDD frame structure available for LTE communication. For example, base station 504 may determine that the narrowband TDD frame structure is either configuration m or n from table 410 of FIG. Configuration m or n from Table 410 may not be available for LTE communication.

In some other aspects, base station 504 may determine a narrowband TDD frame structure from a subset of the configurations from table 410 of FIG. 4 (503). For example, base station 504 may determine a narrowband TDD frame structure from configurations 1, 2, 3, 4, 5, m, and/or n (503). In some aspects, configurations 0 and 6 may not be used due to the narrowband TDD frame structure, which is repeated because configurations 0 and 6 have a smaller number of downlink subframes compared to other configurations. This is because there is a case where the automatic transmission is not supported.

When base station 504 repeats downlink transmissions, base station 504 may repeat at least a minimum number of downlink subframes (e.g., at least 3 downlink subframes such that downlink transmissions may be repeated in each downlink subframe). A narrowband TDD frame structure with downlink subframes) may be chosen.

In some other aspects, the base station 504 is used by the base station 504 and/or the UE 506 to switch from transmitting on downlink subframes to monitoring uplink subframes, and vice versa. A narrowband TDD frame structure for narrowband communication 509 may be determined based on the switching period used (503). For example, when the switching period used by base station 504 and/or UE 506 is longer than the switching period in the LTE TDD frame structure (e.g. configurations 0, 1, 2, 3, 4, 5, and 6), configurations m and n Since both of the switching cycles are longer than 10 ms (eg, 20 ms), the base station 504 may select either the configuration m or the configuration n.

In the first example, the narrowband TDD frame structure determined by base station 504 may be configuration n (see, eg, FIG. 4). Configuration n may include multiple flexible subframes, which may each be dynamically configured by base station 504 as a downlink subframe, an uplink subframe, or a special subframe. Configuration n may provide base station 504 the flexibility to have downlink or uplink transmissions (eg, based on channel conditions) to increase the probability that UE 506 will properly decode the transmissions. ..

In the second example, the narrowband TDD frame structure determined by base station 504 may be one of configurations 3, 4, 5, m, or n (see, eg, FIG. 4). The narrowband TDD frame structures associated with configurations 3, 4, 5, m, and n each include at least three downlink subframes (e.g., flexible subframes in configuration n have three TDD frame structures). (It may be dynamically configured by the base station 504 so as to have the above downlink subframes). Using a narrowband TDD frame structure with at least three downlink subframes, the base station 504 allows the base station 504 to in different subframes of the same radio frame, as described below with reference to FIGS.5B-5D. It may be possible to send NPSS, NSSS, and NPBCH. In some aspects, repeating NPSS, NSSS, and NPBCH may be performed by repeating NPSS, NSSS, and NPBCH over multiple symbols in the same subframe. Configurations 4, 5, m, or n (e.g., configurations with 4 downlink subframes or configurable with 4 downlink subframes) determined to be used as narrowband TDD frame structure If so, the SIB 507 may also be transmitted in a subframe different from the subframe used to transmit the NSSS 505. For example, assuming base station 504 determines that the narrowband TDD frame structure is configuration 5, base station 504 may send NSSS 505 in subframe 5 and SIB 507 in subframe 7.

In some aspects, the base station 504 may use at least three consecutive downlink subframes to repeat the downlink transmission. If a narrowband TDD frame structure is used for repetitive downlink transmissions with less than three consecutive downlink subframes (e.g., configurations 0, 1, and 2 in Figure 4), the repetitive The length of time a transmission is transmitted may be extended compared to the length of time of the same number of repetitions transmitted using a narrowband TDD frame structure with at least 3 consecutive downlink subframes .. For example, the time length can be increased due to the presence of uplink subframes and/or unused flexible subframes located between downlink subframes used to repeat the transmission. is there. Therefore, the probability that channel conditions may change over a repetitive transmission using a narrowband TDD frame structure with less than three consecutive downlink subframes is that the narrowband with at least three consecutive downlink subframes is May be increased compared to repetitive transmissions using the TDD frame structure. Therefore, UE 506 may be less likely to combine repetitive transmissions received in a narrowband TDD frame structure with less than three consecutive downlink subframes.

5B-5D illustrate a data flow 510 that may be used for narrowband communication, according to some aspects of the present disclosure. For example, data flow 500 may be performed by base station 504 and/or UE 506 (eg, base station 504 and UE 506 of FIG. 5A). The base station 504 may correspond to the base stations 102, 180, eNB 310, devices 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'. UE 506 may correspond to UE 104, 350, 1150, 1350, 1550, 1750, 1950, 2350. Additionally, base station 504 and UE 506 may be configured to communicate using narrowband communication 509 (eg, NB-IoT and/or eMTC). For example, UE 506 may be a NB-IoT device and/or an eMTC device. In FIGS. 5B-5D, optional operations are indicated by dotted lines.

Referring to FIG. 5B, base station 504 may operate in in-band mode, guard band mode, or standalone mode (513). In some aspects, the base station 504 may configure the narrowband TDD frame structure for the narrowband communication 509 from the group of narrowband TDD frame structures (eg, the configurations listed in table 410 of FIG. 4) (see FIG. 5D). May be determined (515). In one aspect, each narrowband TDD frame structure in the group of narrowband TDD frame structures may include at least one common downlink subframe, as described below.

NPSS
In some aspects, base station 504 may determine a common subframe to use in transmitting NPSS 521 from the plurality of common subframes (517). For example, when the determined narrowband TDD frame structure is one of the configurations 0, 1, 2, 3, 4, 5, 6, or m, the NPSS 521 is subframe 0 or 1 of subframe 5 Subframes 0 and 5 are common downlink subframes in each of configurations 0, 1, 2, 3, 4, 5, 6, and m. In another example, when the determined narrowband TDD frame structure is determined from a subset of the configurations listed in Table 410 (e.g., one of configurations 1, 2, 3, 4, 5, or 6). , NPSS521 may be transmitted in one of subframe 0, subframe 5, or subframe 9, where subframes 0, 5, and 9 are configured 1, 2, 3, 4, 5. , And 6 are common downlink subframes. Additionally and/or alternatively, the subframes used to transmit NPSS 521 may be a function of the determined narrowband TDD frame structure. In one example, this dependency may be that the first downlink subframe in the narrowband TDD frame structure may be used to transmit the NPSS 521. In some aspects, the period associated with the NPSS transmitted using the narrowband TDD frame structure (e.g., once every 20 ms) is the NPSS transmitted using the narrowband FDD frame structure (e.g., May be shorter or longer than once every 10 ms). Shortening the period of NPSS transmissions (eg, more frequent transmission of NPSSs) may be useful, for example, when the NPSS and NPBCH carriers are different and the NPSS carriers cannot be power up as much as in FDD. In such situations, UE 506 may use additional NPSS averaging to achieve the expanded coverage. To allow transmissions of NPBCH, NPSS, NSSS, SIB, etc. to be accommodated on the same carrier, it may be useful to extend the period of NPSS transmissions (eg, rarer transmission of NPSS).

In some other aspects, base station 504 may determine a sequence (eg, a Zadoff Chu sequence) associated with NPSS 521 (519). In some other aspects, the NPSS sequence 521 may be associated with at least one of the TDD mode or the determined narrowband TDD frame structure. In some other aspects, the NPSS 521 may have the same set of sequences as the NPSS transmitted using the narrowband FDD frame structure. The FDD NPSS sequence may comprise a Zadoff Chu sequence with a root index of 5 and a length of 11, and the same sequence may be sign-inverted on some symbols to provide better timing characteristics. In some other aspects, the NPSS 521 may have a different set of sequences than the NPSS transmitted using the narrowband FDD frame structure. In some other aspects, the NPSS 521 may have a different Zadoff Chu sequence for initialization than the NPSS transmitted in the FDD frame structure. In some other aspects, the NPSS 521 transmitted using the determined narrowband TDD frame structure may have a different cover code than the NPSS transmitted using the narrowband FDD frame structure. The use of different NPSS sequences for narrowband TDD can introduce processing complexity at the UE, but if the UE is aware that some bands only support TDD or FDD, then the UE 506 , To reduce such complexity, we may limit the NPSS search to only one corresponding sequence.

NSSS
Referring to FIG. 5C, base station 504 may transmit NSSS 529 using the determined narrowband TDD frame structure. In one aspect, the period of the NSSS 529 transmitted using the narrowband TDD frame structure is the NSSS transmitted using the narrowband FDD frame structure, transmitted in subframe 9 of every other radio frame. It may be the same as compared to the cycle.

Instead, the NSSS529 period transmitted using the narrowband TDD frame structure is the period of the NSSS transmitted using the narrowband FDD frame structure, transmitted in subframe 9 of every other radio frame. It may be extended compared to. Thus, the NSSS 529 period transmitted using the narrowband TDD frame structure may be more than two radio frames. Prolonging the period for transmitting NSSS529 may be beneficial if there are separate carriers for NPSS521/NSSS529 and NPBCH/SIB, which would otherwise make NSSS subframes unavailable. Because there is. Also, because the NRS may not be on the NSSS carrier, additional NSSS measurements may be needed.

In some aspects, the NSSS 529 may be transmitted using a different RB (eg, carrier) than the RB used to transmit the NPSS 521. In situations where the NPSS521 period is shortened (e.g. NPSS521 is not transmitted in every radio frame) or is extended (e.g. NPSS521 is transmitted in each radio frame or more than once in each radio frame) (Transmitted) situation, the NSSS 529 may be transmitted in a radio frame that does not include the NPSS 521. If there are separate carriers for PSS/SSS and PBCH/SIB, it may make sense to extend the period, because otherwise SSS subframes may not be available. is there. Also, the NRS may no longer exist on its carrier and may therefore require additional SSS for measurements.

Additionally and/or alternatively, NSSS529 and NPSS521 are multiplexed such that one of NSSS529 or NPSS521 is transmitted in an even numbered subframe and the other of NSSS529 or NPSS521 is transmitted in an odd numbered subframe. May be.

In some aspects, base station 504 may determine a common subframe from the plurality of common subframes described above for transmitting NSSS 529 (517). For example, when the narrowband TDD frame structure is determined from one of configurations 0, 1, 2, 3, 4, 5, 6, and m, the NSSS 529 may be one of subframe 0 or subframe 5 , Since subframes 0 and 5 are common downlink subframes in each configuration in the group. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, the NSSS 529 is subframe 0, subframe 5, or subframe 9 May be transmitted in one of the following, because subframes 0, 5, and 9 are common downlink subframes in each of configurations 1, 2, 3, 4, 5, and 6. is there. In one example, the NSSS may be sent in a special subframe, which may cause the NSSS length to be different for narrowband TDD and narrowband FDD configurations.

In one aspect, the base station 504 relies on the determined narrowband TDD frame structure to determine at least one of the NSSS529 period, the NSSS529 temporal position, or the NSSS529 frequency position (as a function of) You may decide (523).

In some aspects, the UE 506 may be able to distinguish between a narrowband FDD frame structure and a narrowband TDD frame structure while performing an NSSS search 527. For example, when a narrowband FDD frame structure is used, the base station 504 sends NPSS521 in subframe 5 of the odd numbered radio frame and NSSS529 in subframe 9 of the even numbered radio frame. You may. In some other aspects, the base station 504 may transmit NPSS 521 in subframe 0 of the odd numbered radio frame and NSSS 529 in subframe 5 of the even numbered radio frame. In some other aspects, the base station 504 may send NPSS 521 in subframe 5 of the even numbered radio frame and NSSS 529 in subframe 0 of the odd numbered radio frame. Based on the subframe numbers and even/odd radio frames used to transmit NPSS521 and NSSS529, UE 506 may either use narrowband FDD frame structure by base station 504 or use narrowband TDD frame structure. It may be possible (for example, implicitly without signaling from the base station 504) to be determined. Additionally and/or alternatively, the UE 506 may be able to determine (531) cell identification information (ID) and timing information based on the NSSS 529. For example, UE 506 may use NSSS to determine cell ID and radio frame boundaries (eg, 20 ms frame boundaries).

Referring to FIG.5C, base station 504 determines a predetermined distance (e.g., subframe distance and/or radio frame boundary) between NPSS 521 and NSSS 529 (525) and uses the predetermined distance to inform. May be communicated to UE 506. For example, a given distance is associated with the TDD mode (e.g., in-band mode, guard band mode, and/or standalone mode) used by base station 504, FDD mode, determined narrowband TDD frame structure, TDD mode. Bandwidth, or may be configured to convey information associated with at least one of theta_f or θ _f mappings associated with the narrowband TDD frame structure and used to indicate the NSSS529 sequence. In narrowband communication using the narrowband FDD frame structure, a mapping of θ _f may be used to indicate the NSSS sequence. For example, θ _f is
May be defined as In narrowband communication using the narrowband TDD frame structure, the mapping of θ _f may be the same as that used for the narrowband FDD frame structure, except that the value of n _f is different. The distance between the NPSS521 and NSSS529 is, UE506 to determine NSSS sequence using mapping theta _f is sometimes used, may be used to convey the value of n _f.

NPBCH
Referring to FIG. 5D, when base station 504 operates in in-band mode, base station 504 may determine in which of the common subframes described above to transmit NPBCH 535 (533). In one aspect, base station 504 may transmit NPBCH 535 on a narrowband carrier that is different than the narrowband carrier used to transmit NPSS 521 and/or NSSS 529.

For example, when the narrowband TDD frame structure is determined from one of configurations 0, 1, 2, 3, 4, 5, 6, and m, the NPBCH 535 is one of subframe 0 or subframe 5 , Since subframes 0 and 5 are common downlink subframes in each configuration in the group. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, NPBCH 535 is subframe 0, subframe 5, or subframe 9 May be transmitted in one of the subframes 0, 5, and 9 because they are common downlink subframes in each configuration in the group. Alternatively, base station 504 may send NPBCH 535 in a radio frame that does not include NSSS 529 (eg, to accommodate NSSS 529).

In some aspects, the period of NPBCH transmissions using the narrowband TDD frame structure may be reduced compared to the period of NPBCH transmissions using the narrowband FDD frame structure.

In some situations, the UE 506 may not know prior to the NPBCH decoding process whether the base station 504 is using a narrowband FDD frame structure or a narrowband TDD frame structure. In such a situation, the UE 506 may make an assumption during the NPBCH decoding process as to whether the base station 504 is using a narrowband FDD frame structure or a narrowband TDD frame structure. .. To avoid situations where the UE 506 assumes a frame structure type, the base station 504 may include information in the NPBCH 535 to indicate to the UE 506 that a narrowband TDD frame structure is being used. For example, base station 504 may include Cyclic Redundancy Check (CRC) masking on NPBCH 535 to indicate that a narrowband TDD frame structure is being used. Additionally and/or alternatively, CRC masking in NPBCH 535 may indicate to UE 506 which configuration the narrowband TDD frame structure uses (see, eg, Table 410 of FIG. 4). Further, inclusion of CRC masking may prevent legacy UEs (eg, UEs that are not configured for narrowband communication using the TDD frame structure) from attempting to decode NPBCH535.

In some other aspects, the period of the NPBCH 535 transmitted by the base station 504, the temporal position of the NPBCH 535, or the frequency position of the NPBCH 535 may be associated with the determined narrowband TDD frame structure.

In addition, the NPBCH 535 may indicate to the UE 506 if a narrowband TDD frame structure is being used, the first bit may indicate to the UE 506 if a narrowband FDD frame structure is being used. The bits may include information indicating the RB position or subframe position associated with the SIB 537 transmitted by the base station 504, or information used to decode the SIB 537. In another aspect, NPBCH 535 may include a single bit that may indicate to UE 506 whether a narrowband TDD frame structure is used or a narrowband FDD frame structure is used.

SIB
In some aspects, the base station 504 uses the same RB and/or a different RB as the RB used to transmit one or more of NPSS521, NSSS529, and/or NPBCH535, and/or SIB537( For example, SIB-1) may be transmitted. The bandwidth used for narrowband communication 509, the type of deployment (e.g., inband mode, guardband mode, standalone mode), and/or the frequency location associated with NPBCH535, which RBs carry SIB537. May be used by the UE 506 to infer what to use.

In some aspects, base station 504 may transmit SIB 537 using one of the common subframes described above. For example, when the narrowband TDD frame structure is one of configurations 0, 1, 2, 3, 4, 5, 6, and m, SIB537 transmits on one of subframe 0 or subframe 5. Subframes 0 and 5 are common downlink subframes in each configuration in the group. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, SIB537 indicates that subframe 0, subframe 5, or subframe 9 May be transmitted in one of the following, because subframes 0, 5, and 9 are common downlink subframes in each of configurations 1, 2, 3, 4, 5, and 6. is there. Alternatively, base station 504 may send SIB537 in a downlink subframe that depends on the determined narrowband TDD frame structure (eg, may send SIB537 in the first downlink subframe). ..

NRS
In some aspects, the base station 504 may transmit the narrowband reference signal (NRS) 541 using the narrowband TDD frame structure determined for the narrowband communication 509. For example, base station 504 may transmit the NRS using subframes that are also used to transmit SIB537 and/or NPBCH535. Additionally, NRS 541 may be transmitted using a narrowband carrier that is different than the narrowband carrier used to transmit NPSS 521 and/or NSSS 529.

In some other aspects, base station 504 may transmit NRS 541 using one of the common subframes described above. For example, when the narrowband TDD frame structure is determined from one of the configurations 0, 1, 2, 3, 4, 5, 6, and m, the NRS 541 is one of subframe 0 or subframe 5 , Since subframes 0 and 5 are common downlink subframes in each configuration in the group. Further, the NRS 541 may be transmitted in subframe 1 or subframe 6, which means that subframes 1 and 6 are special subframes (e.g., including downlink resources) or configurations 0, 1, 2, 3, 4 , 5, 6, and m are downlink subframes. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, the NRS 541 is subframe 0, subframe 5, or subframe 9 May be transmitted in one of the subframes 0, 5, and 9 because they are common downlink subframes in each configuration in the group. Alternatively, base station 504 may send NRS 541 in the downlink subframe that does not depend on the determined narrowband TDD frame structure. For example, the NPBCH 535 (e.g., broadcast signaling) transmitted by the base station 504 may include the NRS 541 when the downlink subframe used to transmit the NRS 541 does not depend on the determined narrowband TDD frame structure. It may be used to indicate the link subframe to the UE 506. In some aspects bitmap 539 may be included in NPBCH 535.

In one aspect, the NRS 541 may be transmitted in the DwPTS portion of the special subframe (eg, see FIG. 4) in the determined narrowband TDD frame structure and in the downlink subframe. In one aspect, the same symbols in the DwPTS portion of the special subframe and the downlink subframe may be used to transmit NRS 541. When the NRS 541 is transmitted in the DwPTS of the special subframe, the UpPTS part of the special subframe may be punctured.

In some aspects, the density of NRS 541 transmitted using a narrowband TDD frame structure may be higher than the density of NRS transmitted using a narrowband FDD frame structure. In other words, the NRS 541 occupancy (eg, density) in the time-frequency grid may be higher in the narrowband TDD frame structure than in the narrowband FDD frame structure. Therefore, higher pilot densities may be used in narrowband TDD frame structures, which, unlike narrowband FDD frame structures, average out channel and/or noise variations in narrowband TDD frame structures. This is because the number of downlink subframes used when performing may be smaller. In some other aspects, NRS 541 may be transmitted in the same subframe that base station 504 uses to transmit the CRS.

FIG. 6 is a flowchart 600 of a method of wireless communication. The method is performed by a base station (e.g., base station 102, 180, 504, eNB310, device 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'). It may be executed. In FIG. 6, the optional actions are indicated by dotted lines.

At 602, a base station may determine a bandwidth for narrowband communication. In one aspect, the bandwidth for narrowband communication is configured as an uplink subframe, downlink subframe, or special subframe, depending on what is being transmitted by either the base station and/or the UE. May include at least one flexible subframe. For example, referring to FIG. 5A, base station 504 may operate in standalone mode (501) and the bandwidth associated with standalone mode (eg, base station 504 decides to use for narrowband communication 509). Bandwidth) may be different from the bandwidth available for LTE communication.

At 604, the base station may determine a narrowband TDD frame structure for narrowband communication. In some configurations, the narrowband TDD frame structure includes two or more consecutive downlink subframes, or one or more flexible subframes that can be configured as either downlink or uplink subframes. It may include a frame. In some other configurations, when the first time length is used by the UE to switch between monitoring downlink subframes and transmitting transmissions using uplink subframes, Special subframes may be placed in both half frames of the narrowband TDD frame structure. In some other configurations, a second time length, which is longer than the first time length, is used to switch between monitoring the downlink subframe and transmitting the transmission using the uplink subframe. When used by the UE, the special subframe may be located in the first half frame of the narrowband TDD frame structure, but not in the second half frame of the narrowband TDD frame structure. There is. In some other configurations, a third time length, which is longer than the second time length, is provided to switch between monitoring the downlink subframe and transmitting the transmission using the uplink subframe. When used by the UE, there are no special subframes in the narrowband TDD frame structure. In some other configurations, the narrowband TDD frame structure for narrowband communication may be different than another TDD frame structure that is actively used in overlapping frequency domains by different RATs. For example, referring to FIG. 5A, base station 504 may determine a narrowband TDD frame structure for narrowband communication 509 (503). In one aspect, the narrowband TDD frame structure determined by the base station 504 may include a TDD frame structure that is different than the LTE TDD frame structure available for LTE communication. For example, base station 504 may determine that the narrowband TDD frame structure is either configuration m or n from table 410 of FIG. When base station 504 repeats downlink transmissions, base station 504 determines at least a minimum number of downlink subframes so that downlink transmissions can be repeated in each of the downlink subframes.
A narrowband TDD frame structure with (eg, at least 3 downlink subframes) may be chosen. By using a narrowband TDD frame structure with at least three downlink subframes, as described above with reference to FIGS.5B-5D, the base station 504 can be configured in different subframes of the same radio frame. It may be possible to send NPSS, NSSS, and NPBCH. In some aspects, repeating NPSS, NSSS, and NPBCH may be performed by repeating NPSS, NSSS, and NPBCH over multiple symbols in the same subframe. Additionally and/or alternatively, base station 504 may base station 504 and/or UE 506 to switch from transmitting on downlink subframes to monitoring uplink subframes, and vice versa. A narrowband TDD frame structure for narrowband communication 509 may be determined based on the switching period used by 503. For example, when the switching period used by base station 504 and/or UE 506 is longer than the switching period in the LTE TDD frame structure (e.g. configurations 0, 1, 2, 3, 4, 5, and 6), configurations m and n Since both of the switching cycles are longer than 10 ms (for example, 20 ms), the base station 504 may select either the configuration m or the configuration n. In some configurations, the narrowband TDD frame structure (e.g., configuration m or n shown in FIG. 4) may include two or more consecutive downlink subframes, or downlink or uplink subframes. It may include one or more flexible subframes that are configurable as such. For example, the narrowband TDD frame structure may include at least three consecutive downlink subframes (eg, configurations 3, 4, 5, and m shown in FIG. 4). In some other configurations, when the first time length is used by UE 506 to switch between monitoring downlink subframes and transmitting transmissions using uplink subframes, Special subframes may be placed in both halves of the narrowband TDD frame structure (eg, configurations 0, 1, 2, and 6 shown in FIG. 4). In some other configurations, a second time length, which is longer than the first time length, is used to switch between monitoring the downlink subframe and transmitting the transmission using the uplink subframe. When used by the UE 506, the special subframe may be located in the first half frame of the narrowband TDD frame structure, but not in the second half frame of the narrowband TDD frame structure. (Eg, configurations 3, 4, and 5 shown in FIG. 4). In some other configurations, a third time length, which is longer than the second time length, is provided to switch between monitoring the downlink subframe and transmitting the transmission using the uplink subframe. When used by UE 506, there are no special subframes in the narrowband TDD frame structure (eg, configuration m shown in FIG. 4). In some other configurations, the narrowband TDD frame structure for narrowband communication (eg, configuration m or n shown in FIG. 4) is differently used by different RATs in the overlapping frequency domain. TDD frame structure (eg, configurations 0, 1, 2, 3, 4, 5, and 6 shown in FIG. 4).

At 606, the base station may send the SIB in the first subframe of the narrowband TDD frame structure. For example, referring to FIG. 5A, one of configurations 4, 5, m, or n (e.g., a configuration with 4 downlink subframes or a configuration that can be configured with 4 downlink subframes). Is determined to be used as a narrowband TDD frame structure, in a subframe different from the subframe used to transmit NSSS 505, as discussed above with respect to FIGS.5B-5D, SIB 507 may also be transmitted. For example, assuming base station 504 determines that the narrowband TDD frame structure includes configuration 5, base station 504 may transmit NSSS 505 in subframe 5 and SIB 507 in subframe 7, or The reverse may be done.

At 608, the base station may send the SSS in the second subframe of the narrowband TDD frame structure. In one aspect, the second subframe may be different than the first subframe. For example, referring to FIG. 5A, one of configurations 4, 5, m, or n (e.g., a configuration with 4 downlink subframes or a configuration that can be configured with 4 downlink subframes). Is determined to be used as the narrowband TDD frame structure, a subframe different from the subframe used to transmit the NSSS 505, as discussed above with reference to FIGS.5B-5D. The SIB 507 may also be transmitted in the frame. For example, assuming base station 504 determines that the narrowband TDD frame structure includes configuration 5, base station 504 may transmit NSSS 505 in subframe 5 and SIB 507 in subframe 7, or The reverse may be done.

At 610, a base station may communicate with a UE using a narrowband TDD frame structure determined for narrowband communication. For example, referring to FIG. 5A, base station 504 and UE 506 may be configured to communicate using narrowband communication 509 (eg, NB-IoT and/or eMTC).

FIG. 7 is a flowchart 700 of a method of wireless communication. The method is performed by a base station (e.g., base station 102, 180, 504, eNB310, device 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'). It may be executed. In FIG. 7, the optional actions are indicated by dotted lines.

At 702, the base station may determine a TDD mode for narrowband communication. For example, referring to FIGS. 5B-5D, base station 504 may operate in in-band mode, guard band mode, or standalone mode (513).

At 704, the base station may determine a TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In one aspect, at least one common subframe in each narrowband TDD frame structure in the group of narrowband TDD frame structures may be configured as a downlink subframe. In another aspect, the first period associated with the PSS using the narrowband TDD frame structure is extended compared to the second period associated with the transmission of the second PSS using the narrowband FDD frame structure. It may be done. For example, referring to FIGS.5B-5D, base station 504 may select a narrowband TDD frame structure for narrowband communication 509 from a group of narrowband TDD frame structures (e.g., configurations listed in table 410 of FIG. 4). May be determined (515). In an aspect, each narrowband TDD frame structure in the group of narrowband TDD frame structures may include at least one common downlink subframe. Base station 504 may determine which of the common subframes to use when transmitting NPSS 521 (515). For example, when the narrowband TDD frame structure is determined from one of configurations 0, 1, 2, 3, 4, 5, 6, and m, the NPSS 521 may be one of subframe 0 or subframe 5 , Subframes 0 and 5 are common downlink subframes in each of configurations 0, 1, 2, 3, 4, 5, 6, and m. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, the NPSS 521 is subframe 0, subframe 5, or subframe 9 May be transmitted in one of the subframes 0, 5, and 9 because they are common downlink subframes in each configuration in the group. Additionally or alternatively, the subframes used to transmit the NPSS 521 may depend on the determined narrowband TDD frame structure. In one example, this dependency may be that the first downlink subframe in the narrowband TDD frame structure may be used to transmit the NPSS 521. In some aspects, the period associated with the NPSS transmission in the narrowband TDD frame structure (eg, once every 20 ms) may be reduced compared to the NPSS transmission in the narrowband FDD frame structure.

At 706, the base station may determine one of the plurality of common subframes for use in transmitting the PSS. In one aspect, one of the plurality of common subframes may be determined as dependent on the narrowband TDD frame structure selected for narrowband communication. For example, referring to FIGS. 5B-5D, base station 504 may determine which of the common subframes to use in transmitting NPSS 521 (515). In some aspects, the NPSS 521 is of subframe 0 or subframe 5 when the narrowband TDD frame structure is determined from one of configurations 0, 1, 2, 3, 4, 5, 6, and m. It may be sent in one of the subframes, since subframes 0 and 5 are common downlink subframes in each configuration in the group. In some other aspects, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, NPSS 521 is configured to subframe 0, subframe 5, or It may be sent in one of the subframes 9, because subframes 0, 5, and 9 are common downlink subframes in each configuration in the group. Additionally or alternatively, the subframes used to transmit the NPSS 521 may depend on the determined narrowband TDD frame structure. In one example, this dependency may be that the first downlink subframe in the narrowband TDD frame structure may be used to transmit the NPSS 521. In some other aspects, the period associated with the NPSS transmission in the narrowband TDD frame structure (eg, once every 20 ms) may be shortened as compared to the NPSS transmission in the narrowband FDD frame structure. ..

At 708, the base station may transmit the PSS using at least one common subframe in the narrowband TDD frame structure determined for narrowband communication. In an aspect, the first period associated with transmitting a PSS using a narrowband TDD frame structure is compared to a second period associated with transmitting a second PSS using a narrowband FDD frame structure. And may be shortened or extended. For example, referring to FIGS. 5B-5D, base station 504 may determine which of the common subframes to use in transmitting NPSS 521 (515). For example, when the narrowband TDD frame structure is determined from one of configurations 0, 1, 2, 3, 4, 5, 6, and m, the NPSS 521 may be one of subframe 0 or subframe 5 , Since subframes 0 and 5 are common downlink subframes in each configuration in the group. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, the NPSS 521 is subframe 0, subframe 5, or subframe 9 May be transmitted in one of the subframes 0, 5, and 9 because they are common downlink subframes in each configuration in the group. Additionally or alternatively, the subframes used to transmit the NPSS 521 may depend on the determined narrowband TDD frame structure. In one example, this dependency may be that the first downlink subframe in the narrowband TDD frame structure may be used to transmit the NPSS 521. In some aspects, the periodicity associated with NPSS transmissions in a narrowband TDD frame structure (eg, once every 20ms) may be reduced compared to NPSS transmissions in a narrowband FDD frame structure. In some aspects, the period associated with the NPSS transmission in the narrowband TDD frame structure (eg, once every 20 ms) may be reduced compared to the NPSS transmission in the narrowband FDD frame structure.

FIG. 8 is a flowchart 800 of a method of wireless communication. The method is performed by a base station (e.g., base station 102, 180, 504, eNB310, device 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'). It may be executed.

At 802, the base station may determine a TDD mode for narrowband communication. For example, referring to FIGS. 5B-5D, base station 504 may operate in in-band mode, guard band mode, or standalone mode (513).

At 804, the base station may determine a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. For example, referring to FIGS.5B-5D, base station 504 may select a narrowband TDD frame structure for narrowband communication 509 from a group of narrowband TDD frame structures (e.g., configurations listed in table 410 of FIG. 4). May be determined (515). In an aspect, each narrowband TDD frame structure in the group of narrowband TDD frame structures may include at least one common downlink subframe. Base station 504 may determine which of the common subframes to use when transmitting NPSS 521 (515). For example, when the narrowband TDD frame structure is determined from one of configurations 0, 1, 2, 3, 4, 5, 6, and m, the NPSS 521 may be one of subframe 0 or subframe 5 , Since subframes 0 and 5 are common downlink subframes in each configuration in the group. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, the NPSS 521 is subframe 0, subframe 5, or subframe 9 May be transmitted in one of the following, because subframes 0, 5, and 9 are common downlink subframes in each of configurations 1, 2, 3, 4, 5, and 6. is there. Additionally or alternatively, the subframes used to transmit the NPSS 521 may depend on the determined narrowband TDD frame structure. In one example, this dependency may be that the first downlink subframe in the narrowband TDD frame structure may be used to transmit the NPSS 521.

At 806, the base station may transmit the PSS using the narrowband TDD frame structure selected for narrowband communication. In an aspect, the set of PSS sequences may be associated with at least one of the TDD mode or the determined narrowband TDD frame structure. In another aspect, the set of PSS sequences transmitted using the narrowband TDD frame structure may be the same as the second set of PSS sequences transmitted using the narrowband FDD frame structure. In a further aspect, the set of PSS sequences transmitted using the narrowband TDD frame structure may be different than the second set of PSS sequences transmitted using the narrowband FDD frame structure. In some other aspects, the set of PSS sequences transmitted using the narrowband TDD frame structure is different from the second set of PSS sequences transmitted using the narrowband FDD frame structure, the initial set May have a Zadoff Chu sequence for optimization. In some other aspects, the set of PSS sequences transmitted using the narrowband TDD frame structure has a different cover code than the second set of PSS sequences transmitted using the narrowband FDD frame structure. May have. For example, referring to FIGS. 5B-5D, base station 504 may determine a sequence associated with NPSS 521 (519). In an aspect, the sequence of NPSS 521 may be associated with at least one of the TDD mode or the determined narrowband TDD frame structure. In some aspects, the NPSS 521 transmitted using the determined narrowband TDD frame structure may have the same sequence as the NPSS transmitted using the narrowband FDD frame structure. In some other aspects, the NPSS 521 transmitted using the determined narrowband TDD frame structure may have a different sequence than the NPSS transmitted using the narrowband FDD frame structure. In some other aspects, the NPSS 521 transmitted using the determined narrowband TDD frame structure may have a different Zadoff Chu sequence for initialization than the NPSS transmitted in the FDD frame structure. is there. In some other aspects, the NPSS 521 transmitted using the determined narrowband TDD frame structure may have a different cover code than the NPSS transmitted using the narrowband FDD frame structure.

FIG. 9 is a flowchart 900 of a method of wireless communication. The method is performed by a base station (e.g., base station 102, 180, 504, eNB310, device 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'). It may be executed. In FIG. 9, the optional action is accompanied by a dotted line.

At 902, the base station may determine a narrowband communication frame structure comprising an FDD mode or a TDD mode and a particular TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In one aspect, at least one common subframe in each narrowband TDD frame structure in the group of narrowband TDD frame structures may be configured as a downlink subframe. In another aspect, the SSS may be transmitted using at least one common subframe in the narrowband TDD frame structure determined for narrowband communication. In a further aspect, the group of narrowband TDD frame structures may include a subset of all narrowband TDD frame structures available for narrowband communication. For example, referring to FIGS.5B-5D, base station 504 may select a narrowband TDD frame structure for narrowband communication 509 from a group of narrowband TDD frame structures (e.g., configurations listed in table 410 of FIG. 4). May be determined (515). NSSS529 transmits on subframe 0 or one of subframe 5 when the narrowband TDD frame structure is determined from one of configurations 0, 1, 2, 3, 4, 5, 6, and m Subframes 0 and 5 are common downlink subframes in each configuration in the group. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, the NSSS 529 is subframe 0, subframe 5, or subframe 9 May be transmitted in one of the subframes 0, 5, and 9 because they are common downlink subframes in each configuration in the group.

At 904, the base station may determine the SSS sequence and a predetermined distance between transmitting the PSS and transmitting the SSS. In an aspect, at least one of the SSS sequence or the predetermined distance may be configured to convey to the UE information associated with narrowband communication. In another aspect, this information is one or more of TDD mode, FDD mode, narrowband TDD frame structure determined for narrowband communication, bandwidth associated with TDD mode, or SSS or PSS. To the second carrier used to transmit, at least one of the frequency offset of the first carrier used to transmit the physical broadcast channel (PBCH) or system information block (SIB). May be included. For example, referring to FIGS.5B-5D, base station 504 determines a predetermined distance (e.g., subframe distance) between NPSS 521 and NSSS 529, and uses that predetermined distance to convey information to UE 506. May be. For example, a given distance is associated with the TDD mode (e.g., in-band mode, guard band mode, and/or standalone mode) used by base station 504, FDD mode, determined narrowband TDD frame structure, TDD mode. Bandwidth or a narrowband TDD frame structure and may be configured to convey information associated with at least one of the ? _f mappings used to indicate the NSSS529 sequence. In narrowband communication using the narrowband FDD frame structure, the mapping of θ _f used to indicate the NSSS sequence is
May be defined as In narrowband communication using the narrowband TDD frame structure, the mapping of θ _f may be the same as that used for the narrowband FDD frame structure, except that the value of n _f is different. The distance between the NPSS521 and NSSS529 may be used to convey the value of n _f which UE506 is sometimes used to determine the NSSS sequence using mapping theta _f.

At 906, the base station may determine a period associated with the SSS, a subframe number, and a transmission sequence based at least in part on the narrowband TDD frame structure. For example, referring to FIGS. 5B-5D, NSSS 529 may be transmitted using a different RB (eg, carrier) than the RB used to transmit NPSS 521. In configurations where the period of NPSS 521 is shortened (eg, NPSS 521 is not transmitted in every radio frame), NSSS 529 may be transmitted in a radio frame that does not include NPSS 521. In one aspect, NSSS 529 may be transmitted in the same subframe number used to transmit NPSS 521, but may not be transmitted in radio frames that do not include NPSS 521. For example, assuming that NPSS 521 is transmitted in subframe 5 in even numbered radio frames, NSSS 529 may be transmitted in subframe 5 in odd numbered radio frames. Alternatively, base station 504 may transmit NPSS 521 in subframe 0 of the odd numbered radio frame and NSSS 529 in subframe 5 of the even numbered radio frame. In another configuration, base station 504 may transmit NPSS 521 in subframe 5 of the even-numbered radio frame and NSSS 529 in subframe 0 of the odd-numbered radio frame.

At 908, the base station may transmit the PSS using the narrowband TDD frame structure determined for narrowband communication. In an aspect, the PSS may be transmitted on a different narrow band carrier than the SSS. In another aspect, the PSS may be transmitted using a particular subframe. In a further aspect, the PSS may not be transmitted in every frame. In a further aspect, the SSS may be transmitted using a particular subframe in at least one frame where the PSS is not transmitted. In yet another aspect, the PSS may be transmitted using a particular subframe. In a still further aspect, the SSS may be transmitted using subframes other than the particular subframe. For example, referring to FIGS. 5B-5D, NSSS 529 may be transmitted using a different RB (eg, carrier) than the RB used to transmit NPSS 521. In configurations where the period of NPSS 521 is shortened (eg, NPSS 521 is not transmitted in every radio frame), NSSS 529 may be transmitted in a radio frame that does not include NPSS 521. In one aspect, NSSS 529 may be transmitted in the same subframe number used to transmit NPSS 521, but may not be transmitted in radio frames that do not include NPSS 521. For example, assuming that NPSS 521 is transmitted in subframe 5 in even numbered radio frames, NSSS 529 may be transmitted in subframe 5 in odd numbered radio frames. Alternatively, base station 504 may transmit NPSS 521 in subframe 0 of the odd numbered radio frame and NSSS 529 in subframe 5 of the even numbered radio frame. In another configuration, base station 504 may transmit NPSS 521 in subframe 5 of the even-numbered radio frame and NSSS 529 in subframe 0 of the odd-numbered radio frame.

At 910, the base station may send the SSS using the narrowband TDD frame structure determined for narrowband communication. In an aspect, the SSS may be transmitted using the same subframe in at most every other frame. In another aspect, the period associated with transmitting the SSS using the narrowband TDD frame structure is extended or compared to the period associated with transmitting the second SSS using the narrowband FDD frame structure. It may be shortened. In a further aspect, at least one of a period associated with transmitting the SSS, a temporal position associated with transmitting the SSS, or a frequency position associated with transmitting the SSS is a narrow band It relates to a narrowband TDD frame structure determined for communication. For example, referring to FIGS. 5B-5D, base station 504 may transmit NSSS 529 using the determined narrowband TDD frame structure. In one aspect, the NSSS 529 may be transmitted in the same subframe of every other radio frame. In other words, the period of NSSS 529 transmitted using the narrowband TDD frame structure may be shortened compared to the period of NSSS transmitted using the narrowband FDD frame structure. Base station 504 may determine at least one of the NSSS 529 period, the NSSS 529 temporal position, or the NSSS 529 frequency position depending on the determined narrowband TDD frame structure (523). ).

FIG. 10 is a flowchart 1000 of a method of wireless communication. The method is performed by a base station (e.g., base station 102, 180, 504, eNB310, device 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'). It may be executed.

At 1002, a base station determines a narrowband communication frame structure comprising an FDD frame structure or a TDD frame structure and a narrowband TDD frame structure structure for narrowband communication from a group of narrowband TDD frame structure structures. Good. For example, referring to FIGs. It may be decided to use any of the TDD frame structures including the narrowband TDD frame structure configuration for (515).

At 1004, a base station, based on a narrowband communication frame structure or TDD frame structure configuration, one or more narrowband carriers and one or more narrowband carriers for transmitting at least one of BCH or SIB1. Subframes within a narrowband carrier may be determined. For example, referring to FIGS.5B-5D, a base station 504 may include one or more narrowband carriers and one or more narrowband carriers for transmitting SIBs (e.g., SIB1) and/or BCH. May be determined. Base station 504 transmits SIB537 using the same RB (e.g., carrier) or different RBs used to transmit one or more of NPSS521, NSSS529, and/or NPBCH535. Good. The bandwidth used for narrowband communication 509, the type of deployment (e.g., inband mode, guardband mode, standalone mode), and/or the location of the frequency associated with NPBCH535, which RB is SIB537 to UE506. It may be used by the UE 506 to infer what will be used to carry.

At 1006, the base station may send the PSS, the SSS, and at least one of the BCH or SIB1 using the narrowband TDD frame structure determined for the narrowband communication. In one aspect, the carrier used to transmit the BCH and/or SIB may be different than the carrier used to transmit one or more of the PSS or SSS. In another aspect, the narrowband carrier used to transmit the BCH may be different than the narrowband carrier used to transmit one or more of the PSS or SSS. In another aspect, the BCH may be transmitted using one or more subframes in every other radio frame. In some other aspects, the SSS may be transmitted using a particular subframe in every other frame. In some other aspects, the BCH may be transmitted using a particular subframe in each frame where the SSS is not transmitted. In some other aspects, the period associated with transmitting the BCH may be used to indicate whether the FDD frame structure or the TDD frame structure is used for narrowband communication. In some other aspects, at least one of a period associated with transmitting the BCH, a temporal position associated with transmitting the BCH, or a frequency position associated with transmitting the BCH. , A narrowband TDD frame structure determined for narrowband communication, a second carrier containing a PSS or SSS, or one or more of the information transmitted on the PSS or SSS. In some other aspects, the first carrier used to transmit the BCH is fixed with respect to the second carrier used to transmit one or more of the PSS or SSS. It may be arranged with a frequency offset. In some other aspects, the BCH is a narrowband TDD frame structure configuration determined for narrowband communication, whether the narrowband communication uses a FDD frame structure or a TDD frame structure, or SIB1 and It includes information indicating at least one of the associated carrier position or subframe position. In some other aspects, this information may include additional bits in the payload, use different CRC masks based on the additional bits, or use different scrambling codes based on the additional bits. May be included in the BCH by at least one of the following: In some other aspects, the first carrier is used to transmit both BCH and SIB1 when the first carrier is different from the second carrier used to transmit PSS and SSS. Sometimes. In some other aspects, SIB1 may be transmitted using a different carrier than the first carrier used to transmit the BCH. In some other aspects, the position of the narrowband carrier relative to the PSS carrier position, or at least one of the subframes used to transmit SIB1, is a narrowband frame structure determined for narrowband communication. May be associated with. For example, referring to FIGS. 5B-5D, base station 504 may transmit NPBCH 535 using the determined narrowband TDD frame structure. In one aspect, the base station 504 may send the NPBCH 535 in a different RB than the RB used to send the NPSS 521 and/or NSSS 529. The UE 506 may not know before the NPBCH decoding process whether the base station 504 is using a narrowband FDD frame structure or a narrowband TDD frame structure. In such a situation, the UE 506 may make an assumption during the NPBCH decoding process as to whether the base station 504 is using a narrowband FDD frame structure or a narrowband TDD frame structure. .. To avoid situations where the UE 506 assumes a frame structure type, the base station 504 may include information in the NPBCH 535 to indicate to the UE 506 that a narrowband TDD frame structure is being used. For example, base station 504 may include CRC masking in NPBCH 535 to indicate that narrowband TDD frame structure is being used. In addition, including CRC masking may prevent legacy UEs (eg, UEs that are not configured for narrowband communication using the TDD frame structure) from attempting to decode NPBCH535. In some aspects, the period of NPBCH 535, the temporal position of NPBCH 535, or the frequency position of NPBCH 535 transmitted by base station 504 may be associated with a determined narrowband TDD frame structure. In addition, the NPBCH 535 may indicate to the UE 506 if a narrowband TDD frame structure is being used, the first bit may indicate to the UE 506 if a narrowband FDD frame structure is being used. The bits may include information indicating the RB position or subframe position associated with the SIB 537 transmitted by the base station 504, or information used to decode the SIB 537.

FIG. 11 is a conceptual dataflow diagram 1100 showing the dataflow between different means/components in an exemplary apparatus 1102. A device is a base station (e.g., base station 102, 180) that is in narrow band communication (e.g., NB-IoT communication or eMTC) with a UE 1150 (e.g., UE 104, 350, 506, 1350, 1550, 1750, 1950, 2350). , 310, 504, devices 1102′, 1302/1302′, 1502/1502′, 1702/1702′, 1902/1902′, 2302/2302′). The apparatus may include a receiving component 1104, a determining component 1106, and a transmitting component 1108.

The determining component 1106 may be configured to determine the bandwidth for narrowband communication. In one aspect, the bandwidth for narrowband communication may be different than the bandwidth available for LTE communication. The determining component 1106 may be configured to determine a narrowband TDD frame structure for narrowband communication. In an aspect, the narrowband TDD frame structure may be different than the LTE TDD frame structure available for LTE communication. In another aspect, the switching period from the downlink subframe to the uplink subframe in the narrowband TDD frame structure may be longer than the switching period in the LTE TDD frame structure. In a further aspect, the narrowband TDD frame structure has at least 3 consecutive downlink subframes. The determining component 1106 is configured to transmit a signal 1101 including information associated with bandwidth for narrowband communication and/or a narrowband TDD frame structure for narrowband communication to a transmitting component 1108. Good.

The sending component 1108 may be configured to send the SIB 1103 to the UE 1150 in the first frame of the narrowband TDD frame structure. The transmission component 1108 may be configured to transmit the SSS 1103 in the second subframe of the narrowband TDD frame structure. In one aspect, the second subframe may be different than the first subframe. The transmitting component 1108 provides the UE 1150 with information 1103 associated with bandwidth for narrowband communication and/or information associated with one or more of information 1103 of narrowband TDD frame structure for narrowband communication. It may be configured to transmit.

The receiving component 1104 and/or the transmitting component 1108 may be configured to communicate (1103, 1105) with the UE 1150 using a narrowband TDD frame structure determined for narrowband communication. For example, receiving component 1104 may be configured to receive narrowband uplink transmission 1105 from UE 1150. Transmission component 1108 may be configured to transmit one or more narrowband downlink transmissions 1103 to UE 1150.

The apparatus may include additional components that implement each of the blocks of the algorithm in the above-described flowchart of FIG. Thus, each block in the flowchart of FIG. 6 above may be performed by a component, and an apparatus may include one or more of those components. A component is one or more hardware components specifically configured to perform the described process/algorithm, or by a processor configured to perform the described process/algorithm. It may be implemented, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

FIG. 12 is a diagram 1200 illustrating an example hardware implementation of a device 1102′ that utilizes a processing system 1214. Processing system 1214 may be implemented with a bus architecture represented generally by bus 1224. Bus 1224 may include any number of interconnecting buses and bridges depending on the particular application of processing system 1214 and the overall design constraints. Bus 1224 links together various circuits including one or more processor and/or hardware components represented by processor 1204, components 1104, 1106, 1108, and computer readable media/memory 1206. Bus 1224 may also connect various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore These circuits will not be described further.

The processing system 1214 may be coupled to the transceiver 1210. Transceiver 1210 is coupled to one or more antennas 1220. Transceiver 1210 provides a means for communicating with a variety of other devices via a transmission medium. Transceiver 1210 receives signals from one or more antennas 1220, extracts information from the received signals, and provides the extracted information to processing system 1214, particularly receiving component 1104. In addition, the transceiver 1210 receives information from the processing system 1214, particularly the transmitting component 1108, and based on the received information, generates a signal to be applied to one or more antennas 1220. The processing system 1214 includes a processor 1204 coupled to a computer-readable medium/memory 1206. Processor 1204 is responsible for general processing, including execution of software stored in computer-readable media/memory 1206. The software, when executed by the processor 1204, causes the processing system 1214 to perform the various functions described above for any particular device. Computer readable media/memory 1206 may also be used to store data manipulated by processor 1204 when executing software. The processing system 1214 further includes at least one of the components 1104, 1106, 1108. These components are software components that operate within processor 1204 and reside/store in computer readable media/memory 1206, one or more hardware components coupled to processor 1204, or those. May be some combination. Processing system 1214 may be a component of eNB 310 and may include memory 376 and/or at least one of TX processor 316, RX processor 370, and controller/processor 375.

In some aspects an apparatus 1102/1102′ for wireless communication may include means for determining bandwidth for narrowband communication. In one aspect, the bandwidth for narrowband communication may be different than the bandwidth available for LTE communication. In some other aspects, an apparatus 1102/1102′ for wireless communication may include means for determining a narrowband TDD frame structure for narrowband communication. In an aspect, the narrowband TDD frame structure may be different than the LTE TDD frame structure available for LTE communication. In another aspect, the switching period from the downlink subframe to the uplink subframe in the narrowband TDD frame structure may be longer than the switching period in the LTE TDD frame structure. In a further aspect, the narrowband TDD frame structure has at least 3 consecutive downlink subframes. In some other aspects, an apparatus 1102/1102′ for wireless communication may include means for transmitting a SIB in a first frame structure of a narrowband TDD frame structure. In some other aspects, an apparatus 1102/1102′ for wireless communication may include means for transmitting an SSS in a second frame of a narrowband TDD frame structure. In one aspect, the second subframe may be different than the first subframe. In some other aspects, an apparatus 1102/1102′ for wireless communication may include means for communicating with a UE using a narrowband TDD frame structure determined for narrowband communication. The above-mentioned means may be one or more of the above-mentioned components of the processing system 1214 of the device 1102 and/or the device 1102′ configured to perform the functions enumerated by the above-mentioned means. As described above, processing system 1214 may include TX processor 316, RX processor 370, and controller/processor 375. Thus, in one configuration, the means described above may be TX processor 316, RX processor 370, and controller/processor 375 configured to perform the functions recited by the means described above.

FIG. 13 is a conceptual dataflow diagram 1300 showing the dataflow between different means/components in an exemplary apparatus 1302. The device is a base station (e.g., base station 102, 180) that is in narrow band communication (e.g., NB-IoT communication or eMTC) with UE 1350 (e.g., UE 104, 350, 506, 1150, 1550, 1750, 1950, 2350). , 310, 504, devices 1102/1102', 1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'). The device may include a receiving component 1304, a determining component 1306, and a transmitting component 1308.

The decision component 1306 may be configured to determine a TDD mode for narrowband communication. The determining component 1306 may also be configured to determine a TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In one aspect, at least one common subframe in each narrowband TDD frame structure in the group of narrowband TDD frame structures may be configured as a downlink subframe. In another aspect, the first period associated with the PSS using the narrowband TDD frame structure is extended compared to the second period associated with the transmission of the second PSS using the narrowband FDD frame structure. It may be done. The determining component 1306 may be configured to determine one of the common subframes for use in transmitting the PSS. In one aspect, one of the plurality of common subframes may be determined as dependent on the narrowband TDD frame structure selected for narrowband communication. The decision component 1306 determines information associated with one or more of a TDD mode for narrowband communication, a TDD frame structure for narrowband communication, and/or one of a plurality of common subframes. The containing signal 1301 may be configured to be transmitted to the transmitting component 1308.

Transmission component 1308 is associated with information 1303 associated with one or more of a TDD mode for narrowband communication, a TDD frame structure for narrowband communication, and/or one of a plurality of common subframes. May be configured to be transmitted to the UE 1350. The transmitting component 1308 may also be configured to transmit the PSS 1303 (e.g., NPSS) using at least one common subframe in the narrowband TDD frame structure determined for narrowband communication. Good. In one aspect, the first period associated with transmitting the PSS 1303 using the narrowband TDD frame structure is compared to the second period associated with transmitting the second PSS 1303 using the narrowband FDD frame structure. And may be extended.

The receiving component 1304 and/or the transmitting component 1308 may be configured to communicate (1303, 1305) with the UE 1350 using a narrowband TDD frame structure determined for narrowband communication. For example, receiving component 1304 may be configured to receive narrowband uplink transmission 1305 from UE 1350. Transmission component 1308 may be configured to transmit one or more narrowband downlink transmissions 1303 to UE 1350.

The apparatus may include additional components that implement each of the blocks of the algorithm in the above-described flowchart of FIG. Thus, each block in the flowchart of FIG. 7 above may be performed by a component, and a device may include one or more of those components. A component is one or more hardware components specifically configured to perform the described process/algorithm, or by a processor configured to perform the described process/algorithm. It may be implemented, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

FIG. 14 is a diagram 1400 illustrating an example hardware implementation of a device 1302′ utilizing a processing system 1414. Processing system 1414 may be implemented with a bus architecture represented generally by bus 1424. Bus 1424 may include any number of interconnecting buses and bridges depending on the particular application of processing system 1414 and the overall design constraints. Bus 1424 links together various circuits including one or more processor and/or hardware components represented by processor 1404, components 1304, 1306, 1308, and computer readable media/memory 1406. Bus 1424 may also connect various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore These circuits will not be described further.

The processing system 1414 may be coupled to the transceiver 1410. Transceiver 1410 is coupled to one or more antennas 1420. Transceiver 1410 provides a means for communicating with a variety of other devices via a transmission medium. Transceiver 1410 receives signals from one or more antennas 1420, extracts information from the received signals, and provides the extracted information to processing system 1414, particularly receiving component 1304. In addition, the transceiver 1410 receives information from the processing system 1414, and in particular from the transmitting component 1308, and generates a signal to be applied to one or more antennas 1420 based on the received information. Processing system 1414 includes a processor 1404 coupled to a computer-readable medium/memory 1406. Processor 1404 is responsible for general processing, including execution of software stored in computer-readable media/memory 1406. The software, when executed by the processor 1404, causes the processing system 1414 to perform the various functions described above for any particular device. Computer readable media/memory 1406 may also be used to store data manipulated by processor 1404 when executing software. Processing system 1414 further includes at least one of components 1304, 1306, 1308. A component is one or more hardware components coupled to processor 1404, which is a software component executing within processor 1404, resident/stored in computer readable media/memory 1406. Or any combination thereof. Processing system 1414 may be a component of base station 310 and may include memory 376 and/or at least one of TX processor 316, RX processor 370, and controller/processor 375.

In some aspects an apparatus 1302/1302′ for wireless communication may include means for determining a TDD mode for narrowband communication. In some other aspects, an apparatus 1302/1302′ for wireless communication may include means for determining a TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In one aspect, at least one common subframe in each narrowband TDD frame structure in the group of narrowband TDD frame structures may be configured as a downlink subframe. In another aspect, the first period associated with the PSS using the narrowband TDD frame structure is extended compared to the second period associated with the transmission of the second PSS using the narrowband FDD frame structure. It may be done. In some other aspects, an apparatus 1302/1302′ for wireless communication may include means for determining one of a plurality of common subframes for use in transmitting a PSS. .. In one configuration, one of the plurality of common subframes may be determined as dependent on the narrowband TDD frame structure selected for narrowband communication. In some other aspects, an apparatus 1302/1302′ for wireless communication transmits a PSS using at least one common subframe in a narrowband TDD frame structure determined for narrowband communication. May be included. In one aspect, a first period associated with transmitting a PSS using a narrowband TDD frame structure is compared to a second period associated with transmitting a second PSS using a narrowband FDD frame structure. And may be extended. The above-mentioned means may be one or more of the above-mentioned components of the processing system 1414 of the device 1302 and/or the device 1302′ configured to perform the functions enumerated by the above-mentioned means. As described above, processing system 1414 may include TX processor 316, RX processor 370, and controller/processor 375. Thus, in one configuration, the means described above may be TX processor 316, RX processor 370, and controller/processor 375 configured to perform the functions recited by the means described above.

FIG. 15 is a conceptual dataflow diagram 1500 showing the dataflow between different means/components in an exemplary apparatus 1502. A device is a base station (e.g., base station 102, 180) that is in narrow band communication (e.g., NB-IoT communication or eMTC) with a UE 1550 (e.g., UE 104, 350, 506, 1150, 1350, 1750, 1950, 2350). , 310, 504, devices 1102/1102', 1302/1302', 1502', 1702/1702', 1902/1902', 2302/2302'). The apparatus may include a receiving component 1504, a determining component 1506, and a transmitting component 1508.

The decision component 1506 may be configured to determine a TDD mode for narrowband communication. The determining component 1506 may be configured to determine a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. The decision component 1506 may also be configured to transmit a signal 1501 that includes information associated with one or more of a TDD mode for narrowband communication or a narrowband TDD frame structure for narrowband communication. Good.

The transmitting component 1508 may be configured to transmit the PSS 1503 using the narrowband TDD frame structure selected for narrowband communication. In an aspect, the sequence of PSS 1503 may be associated with at least one of the TDD mode or the determined narrowband TDD frame structure. In another aspect, the PSS sequence transmitted using the narrowband TDD frame structure may be the same as the second PSS sequence transmitted using the narrowband FDD frame structure. In a further aspect, the PSS sequence transmitted using the narrowband TDD frame structure may be different than the second PSS sequence transmitted using the narrowband FDD frame structure. In some other aspects, the PSS sequence transmitted using the narrowband TDD frame structure is different from the second PSS sequence transmitted using the narrowband FDD frame structure for initialization. May have the Zadoff Chu sequence. In some other aspects, the PSS sequence transmitted using the narrowband TDD frame structure may have a different cover code than the second PSS sequence transmitted using the narrowband FDD frame structure. is there. The sending component 1508 may be configured to send information 1503 associated with one or more of a TDD mode for narrowband communication or a narrowband TDD frame structure for narrowband communication.

The receiving component 1504 and/or the transmitting component 1508 may be configured to communicate (1503, 1505) with the UE 1550 using a narrowband TDD frame structure determined for narrowband communication. For example, receiving component 1504 may be configured to receive narrowband uplink transmission 1505 from UE 1550. Transmission component 1508 may be configured to transmit one or more narrowband downlink transmissions 1503 to UE 1550.

The apparatus may include additional components that implement each of the blocks of the algorithm in the above flowchart of FIG. Thus, each block in the above-described flowchart of FIG. 8 may be performed by one component and an apparatus may include one or more of those components. A component is one or more hardware components specifically configured to perform the described process/algorithm, or by a processor configured to perform the described process/algorithm. It may be implemented, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

FIG. 16 is a diagram 1600 illustrating an example hardware implementation of a device 1502′ that utilizes a processing system 1614. Processing system 1614 may be implemented using a bus architecture represented generally by bus 1624. Bus 1624 may include any number of interconnect buses and bridges depending on the particular application of processing system 1614 and the overall design constraints. Bus 1624 links together various circuits including one or more processor and/or hardware components represented by processor 1604, components 1504, 1506, 1508, and computer readable media/memory 1606. Bus 1624 may also connect various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore These circuits will not be described further.

The processing system 1614 may be coupled to the transceiver 1610. Transceiver 1610 is coupled to one or more antennas 1620. Transceiver 1610 provides a means for communicating with a variety of other devices via a transmission medium. Transceiver 1610 receives signals from one or more antennas 1620, extracts information from the received signals, and provides the extracted information to processing system 1614, particularly receiving component 1504. In addition, the transceiver 1610 receives information from the processing system 1614, and in particular the transmitting component 1508, and based on the received information, generates a signal to be applied to one or more antennas 1620. The processing system 1614 includes a processor 1604 coupled to a computer-readable medium/memory 1606. Processor 1604 is responsible for general processing, including execution of software stored in computer readable media/memory 1606. The software, when executed by the processor 1604, causes the processing system 1614 to perform the various functions described above for any particular device. Computer readable media/memory 1606 may also be used to store data manipulated by processor 1604 when executing software. Processing system 1614 further includes at least one of components 1504, 1506, 1508. These components are software components that operate within processor 1604 and reside/are stored in computer readable media/memory 1606, one or more hardware components coupled to processor 1604, or those. May be some combination. Processing system 1614 may be a component of base station 310 and may include memory 376 and/or at least one of TX processor 316, RX processor 370, and controller/processor 375.

In some aspects an apparatus 1502/1502′ for wireless communication may include means for determining a TDD mode for narrowband communication. In some other aspects, an apparatus 1502/1502′ for wireless communication may include means for determining a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In some other aspects, an apparatus 1502/1502′ for wireless communication may include means for transmitting a PSS using a narrowband TDD frame structure selected for narrowband communication. In an aspect, the sequence of PSSs may be associated with at least one of the TDD mode or the determined narrowband TDD frame structure. In another aspect, the PSS sequence transmitted using the narrowband TDD frame structure may be the same as the second PSS sequence transmitted using the narrowband FDD frame structure. In a further aspect, the PSS sequence transmitted using the narrowband TDD frame structure may be different than the second PSS sequence transmitted using the narrowband FDD frame structure. In some other aspects, the PSS sequence transmitted using the narrowband TDD frame structure is different from the second PSS sequence transmitted using the narrowband FDD frame structure for initialization. May have the Zadoff Chu sequence. In some other aspects, the PSS sequence transmitted using the narrowband TDD frame structure may have a different cover code than the second PSS sequence transmitted using the narrowband FDD frame structure. is there. The above-mentioned means may be one or more of the above-mentioned components of the processing system 1614 of the device 1502 and/or the device 1502′ configured to perform the functions enumerated by the above-mentioned means. As described above, processing system 1614 may include TX processor 316, RX processor 370, and controller/processor 375. Thus, in one configuration, the means described above may be TX processor 316, RX processor 370, and controller/processor 375 configured to perform the functions recited by the means described above.

FIG. 17 is a conceptual dataflow diagram 1700 showing the dataflow between different means/components in an exemplary apparatus 1702. A device is a base station (e.g., base station 102, 180) that is in narrow band communication (e.g., NB-IoT communication or eMTC) with a UE 1750 (e.g., UE 104, 350, 506, 1150, 1350, 1550, 1950, 2350). , 310, 504, devices 1102/1102', 1302/1302', 1502/1502', 1702', 1902/1902', 2302/2302'). The apparatus may include a receiving component 1704, a determining component 1706, and a transmitting component 1708.

The determining component 1706 may also be configured to determine a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In one aspect, at least one common subframe in each narrowband TDD frame structure in the group of narrowband TDD frame structures may be configured as a downlink subframe. In another aspect, the SSS may be transmitted using at least one common subframe in the narrowband TDD frame structure determined for narrowband communication. In a further aspect, the group of narrowband TDD frame structures may include a subset of all narrowband TDD frame structures available for narrowband communication. The determining component 1706 may be configured to determine a predetermined distance between transmitting the PSS and transmitting the SSS. In an aspect, the predetermined distance may be configured to convey to the UE information associated with narrowband communication. In another aspect, this information may include at least one of a TDD mode, an FDD mode, a narrowband TDD frame structure determined for narrowband communication, or a bandwidth associated with the TDD mode. .. The decision component 1706 includes a narrowband TDD frame structure for narrowband communication and/or information associated with at least one of a predetermined distance between transmitting a PSS and transmitting an SSS. The signal 1701 may be configured to be transmitted to the transmission component 1708.

The transmitting component 1708 may be configured to transmit the PSS 1703 using the narrowband TDD frame structure determined for narrowband communication. In an aspect, PSS 1703 may be transmitted on a different resource block than SSS. In another aspect, PSS 1703 may be transmitted using a particular subframe. In a further aspect, PSS 1703 may not be transmitted in every frame. In a further aspect, SSS1703 may be transmitted using a particular subframe in at least one frame in which PSS1703 is not transmitted. In yet another aspect, PSS 1703 may be transmitted using specific subframes in every other frame. In a still further aspect, SSS1703 may be transmitted using a subframe other than the specific subframe in each frame in which PSS1703 is not transmitted. The sending component 1708 may be configured to send the SSS 1703 using the narrowband TDD frame structure determined for narrowband communication. In an aspect, SSS 1703 may be transmitted using the same subframe in at most every other frame. In another aspect, the period associated with transmitting the SSS1703 using the narrowband TDD frame structure is reduced as compared to the period associated with transmitting the second SSS1703 using the narrowband FDD frame structure. May be. In a further aspect, at least one of a period associated with transmitting SSS1703, a temporal position associated with transmitting SSS1703, or a frequency position associated with transmitting SSS1703 is narrowband. It relates to a narrowband TDD frame structure determined for communication.

The receiving component 1704 and/or the transmitting component 1708 may be configured to communicate (1703, 1705) with the UE 1750 using a narrowband TDD frame structure determined for narrowband communication. For example, receiving component 1704 may be configured to receive narrowband uplink transmission 1705 from UE 1750. Transmission component 1708 may be configured to send one or more narrowband downlink transmissions 1703 to UE 1750.

The apparatus may include additional components that implement each of the blocks of the algorithm in the above-described flowchart of FIG. Thus, each block in the flowchart of FIG. 9 above may be performed by a component, and an apparatus may include one or more of those components. A component is one or more hardware components specifically configured to perform the described process/algorithm, or by a processor configured to perform the described process/algorithm. It may be implemented, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

FIG. 18 is a drawing 1800 illustrating an example of a hardware implementation of a device 1702′ that utilizes a processing system 1814. Processing system 1814 may be implemented using a bus architecture represented generally by bus 1824. Bus 1824 may include any number of interconnect buses and bridges depending on the particular application of processing system 1814 and the overall design constraints. Bus 1824 links together various circuits including one or more processor and/or hardware components represented by processor 1804, components 1704, 1706, 1708, and computer readable media/memory 1806. Bus 1824 may also connect various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore These circuits will not be described further.

The processing system 1814 may be coupled to the transceiver 1810. The transceiver 1810 is coupled to one or more antennas 1820. Transceiver 1810 provides a means for communicating with a variety of other devices via a transmission medium. Transceiver 1810 receives signals from one or more antennas 1820, extracts information from the received signals, and provides the extracted information to processing system 1814, particularly receiving component 1704. In addition, the transceiver 1810 receives information from the processing system 1814, particularly the transmitting component 1708, and based on the received information, generates a signal to be applied to one or more antennas 1820. The processing system 1814 includes a processor 1804 coupled to a computer-readable medium/memory 1806. Processor 1804 is responsible for general processing, including execution of software stored in computer-readable media/memory 1806. The software, when executed by the processor 1804, causes the processing system 1814 to perform the various functions described above for any particular device. Computer readable media/memory 1806 may also be used to store data manipulated by processor 1804 when executing software. Processing system 1814 further includes at least one of components 1704, 1706, 1708. These components are software components that operate within processor 1804 and reside/are stored in computer readable media/memory 1806, one or more hardware components coupled to processor 1804, or those. May be some combination. Processing system 1814 may be a component of base station 310 and may include memory 376 and/or at least one of TX processor 316, RX processor 370, and controller/processor 375.

In some aspects an apparatus 1702/1702′ for wireless communication may include means for determining a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In one aspect, at least one common subframe in each narrowband TDD frame structure in the group of narrowband TDD frame structures may be configured as a downlink subframe. In another aspect, the SSS may be transmitted using at least one common subframe in the narrowband TDD frame structure determined for narrowband communication. In a further aspect, the group of narrowband TDD frame structures may include a subset of all narrowband TDD frame structures available for narrowband communication. In some other aspects, an apparatus 1702/1702′ for wireless communication may include means for determining a predetermined distance between transmitting PSS and transmitting SSS. In an aspect, the predetermined distance may be configured to convey to the UE information associated with narrowband communication. In another aspect, this information may include at least one of a TDD mode, an FDD mode, a narrowband TDD frame structure determined for narrowband communication, or a bandwidth associated with the TDD mode. .. In some other aspects, an apparatus 1702/1702′ for wireless communication may include means for transmitting a PSS using a narrowband TDD frame structure determined for narrowband communication. In an aspect, the PSS may be sent on a different resource block than the SSS. In another aspect, the PSS may be transmitted using a particular subframe. In a further aspect, the PSS may not be transmitted in every frame. In a further aspect, the SSS may be transmitted using a particular subframe in at least one frame where the PSS is not transmitted. In yet another aspect, PSS may be transmitted using specific subframes in every other frame. In a still further aspect, the SSS may be transmitted using a subframe other than the specific subframe in each frame in which the PSS is not transmitted. In some other aspects, an apparatus 1702/1702′ for wireless communication may include means for transmitting an SSS using a narrowband TDD frame structure determined for narrowband communication. In an aspect, the SSS may be transmitted using the same subframe in at most every other frame. In another aspect, the period associated with transmitting the SSS using the narrowband TDD frame structure is shortened as compared to the period associated with transmitting the second SSS using the narrowband FDD frame structure. May be. In a further aspect, at least one of a period associated with transmitting the SSS, a temporal position associated with transmitting the SSS, or a frequency position associated with transmitting the SSS is a narrow band It relates to a narrowband TDD frame structure determined for communication. The above-mentioned means may be one or more of the above-mentioned components of the processing system 1814 of the device 1702 and/or the device 1702' configured to perform the functions recited by the above-mentioned means. As described above, processing system 1814 may include TX processor 316, RX processor 370, and controller/processor 375. Thus, in one configuration, the means described above may be TX processor 316, RX processor 370, and controller/processor 375 configured to perform the functions recited by the means described above.

FIG. 19 is a conceptual dataflow diagram 1900 showing the dataflow between different means/components in an exemplary apparatus 1902. The apparatus is a base station (e.g., base station 102, 180) that is in narrow band communication (e.g., NB-IoT communication or eMTC) with UE 1950 (e.g., UE 104, 350, 506, 1150, 1350, 1550, 1750, 2350). , 310, 504, devices 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902', 2302/2302'). The apparatus may include a receiving component 1904, a determining component 1906, and a transmitting component 1908.

The determining component 1906 may also be configured to determine a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In one aspect, the narrowband TDD frame structure includes a downlink subframe and a set of two or more special subframes. In some other configurations, the decision component 1906 is configured to configure the set of narrowband carriers and the set of narrowband carriers based at least in part on the downlink subframe and the set of two or more special subframes on which the NRS is to be transmitted. It may be configured to determine a minimal set of subframes on the set of narrowband carriers. The decision component 1906 may be configured to send a signal 1901 containing information associated with a narrowband TDD frame structure for narrowband communication to a transmission component 1908.

The sending component 1908 may be configured to send the PSS 1903, SSS 1903, and BCH 1903 using the narrowband TDD frame structure determined for narrowband communication. In one aspect, the resource blocks used to transmit BCH 1903 may be different than the resource blocks used to transmit one or more of PSS 1903 or SSS 1903. In another aspect, BCH 1903 may be transmitted using one or more subframes in every other radio frame. In a further aspect, SSS 1903 may be transmitted using a particular subframe in every other frame. In yet another aspect, BCH 1903 may be transmitted using a particular subframe in each frame where SSS is not transmitted. In a still further aspect, the first cycle associated with transmitting BCH1903 using a narrowband TDD frame structure is compared to the second cycle associated with transmitting BCH1903 using the FDD frame structure. And may be shortened. In another aspect, CRC masking may be included in BCH 1903 to indicate a narrowband TDD frame structure. In another aspect, at least one of a period associated with transmitting BCH 1903, a temporal position associated with transmitting BCH, or a frequency position associated with transmitting BCH 1903 is narrow. It may relate to a narrowband TDD frame structure determined for band communication. In another aspect, the BCH 1903 is a first bit indicating a narrowband TDD frame structure determined for narrowband communication, a second bit indicating a FDD frame structure determined for narrowband communication, or SIB1903. It may include at least one of information indicating a resource block position or a subframe position associated with. The sending component 1908 may be configured to send the SIB 1903 using the narrowband TDD frame structure determined for narrowband communication. In one aspect, SIB1903 may be transmitted using the same resource blocks used to transmit one or more of PSS1903, SSS1903, or BCH1903. In another aspect, SIB1903 may be transmitted using a resource block that is different from the resource block used to transmit one or more of PSS1903, SSS1903, or BCH1903. In a further aspect, at least one of the resource blocks or subframes used to transmit SIB1903 may be associated with a narrowband TDD frame structure determined for narrowband communication. Transmission component 1908 may be configured to transmit information indicating additional subframes used to transmit NRS 1903. In one aspect, the information may include broadcast signaling. The sending component 1908 may be configured to send the NRS 1903 using the narrowband TDD frame structure determined for narrowband communication. In one aspect, NRS 1903 may be transmitted using subframes that are also used to transmit SIB 1903 and BCH 1903. In another aspect, NRS 1903 may be transmitted using a resource block that is different than the resource block used to transmit at least one of PSS 1903 or SSS 1903. In another aspect, the same subframes used to transmit NRS1903, SIB1903, and BCH1903 may not depend on the narrowband TDD frame structure determined for narrowband communication. In a further aspect, the same subframes used to transmit NRS 1903, SIB 1903, and BCH 1903 may depend on the narrowband TDD frame structure determined for narrowband communication. In another aspect, the density of NRS 1903 transmitted using the narrowband TDD frame structure may be increased compared to the density of NRS 1903 transmitted using the narrowband FDD frame structure. In yet another aspect, NRS 1903 may be transmitted in symbols and resource elements used to transmit CRS. In a still further aspect, NRS 1903 may be transmitted in the downlink portion of the special subframe in the narrowband TDD frame structure determined for narrowband communication. In one aspect, the symbols used to transmit the NRS in the downlink portion of the special subframe are the same as the symbols used to transmit the NRS in the downlink subframe in the narrowband TDD frame structure. It may be. In another aspect, any NRS symbol present in the uplink part of the special subframe may be punctured. In a further aspect, the symbols used to transmit NRS1903 in the downlink portion of the special subframe are different than the symbols used to transmit NRS1903 in the downlink subframe in the narrowband TDD frame structure. Good. In some aspects, NRS 1903 may be transmitted on a carrier that includes SIB 1903 or BCH 1903. In some other configurations, the minimal set of subframes includes the subframes used to transmit SIB1903 and BCH1903. In some other aspects, the minimum set of subframes used to transmit NRS 1903 may not depend on the narrowband TDD frame structure determined for narrowband communication. In some other configurations, the minimum set of subframes may be constrained to subframes that are downlink subframes or special subframes in all supported TDD frame structures for narrowband communication. .. In some aspects, the minimum set of subframes used to transmit NRS 1903 may depend on the narrowband TDD frame structure determined for narrowband communication.

The receiving component 1904 and/or the transmitting component 1908 may be configured to communicate (1903, 1905) with the UE 1950 using a narrowband TDD frame structure determined for narrowband communication. For example, receiving component 1904 may be configured to receive narrowband uplink transmission 1905 from UE 1950. The transmission component 1908 may be configured to send one or more narrowband downlink transmissions 1903 to the UE 1950.

The apparatus may include additional components that implement each of the algorithm blocks in the above-described flowcharts of FIGS. 10 and 25. Thus, each block in the above-described flowcharts of FIGS. 10 and 25 may be performed by one component, and an apparatus may include one or more of those components. A component is one or more hardware components specifically configured to perform the described process/algorithm, or by a processor configured to perform the described process/algorithm. It may be implemented, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

FIG. 20 is a diagram 2000 illustrating an example of a hardware implementation of a device 1902′ that utilizes the processing system 2014. Processing system 2014 may be implemented with a bus architecture represented generally by bus 2024. Bus 2024 may include any number of interconnected buses and bridges depending on the particular application of processing system 2014 and the overall design constraints. Bus 2024 links together various circuits including one or more processor and/or hardware components represented by processor 2004, components 1904, 1906, 1908, and computer readable media/memory 2006. Bus 2024 may also connect various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore These circuits will not be described further.

The processing system 2014 may be coupled to the transceiver 2010. Transceiver 2010 is coupled to one or more antennas 2020. Transceiver 2010 provides a means for communicating with a variety of other devices via a transmission medium. The transceiver 2010 receives signals from one or more antennas 2020, extracts information from the received signals, and provides the extracted information to the processing system 2014, specifically the receiving component 1904. In addition, the transceiver 2010 receives information from the processing system 2014, in particular the transmitting component 1908, and based on the received information, generates a signal to be applied to the one or more antennas 2020. The processing system 2014 includes a processor 2004 coupled to a computer-readable medium/memory 2006. Processor 2004 is responsible for general processing, including execution of software stored on computer readable media/memory 2006. The software, when executed by the processor 2004, causes the processing system 2014 to perform the various functions described above for any particular device. Computer readable media/memory 2006 may also be used to store data manipulated by processor 2004 when executing software. The processing system 2014 further includes at least one of the components 1904, 1906, 1908. These components are software components that operate within the processor 2004 and reside/are stored in a computer-readable medium/memory 2006, one or more hardware components coupled to the processor 2004, or those. May be some combination. Processing system 2014 may be a component of base station 310 and may include memory 376 and/or at least one of TX processor 316, RX processor 370, and controller/processor 375.

In some aspects an apparatus 1902/1902′ for wireless communication may include means for determining a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. In some configurations, the narrowband TDD frame structure may include a downlink subframe and a set of two or more special subframes. In some other aspects, an apparatus 1902/1902′ for wireless communication is based at least in part on a downlink subframe and a set of two or more special subframes on which NRS is to be transmitted, Means for determining a set of narrowband carriers and a minimal set of subframes on the set of narrowband carriers may be included. In some other aspects, an apparatus 1902/1902′ for wireless communication uses a narrowband TDD frame structure determined for narrowband communication to transmit PSS, SSS, and BCH. Means may be included. In one aspect, the resource blocks used to transmit the BCH may be different than the resource blocks used to transmit one or more of the PSS or SSS. In another aspect, the BCH may be transmitted using one or more subframes in every other radio frame. In a further aspect, the SSS may be transmitted using specific subframes in every other frame. In yet another aspect, BCH may be transmitted using a particular subframe in each frame where SSS is not transmitted. In a still further aspect, the first period associated with transmitting the BCH using the narrowband TDD frame structure is compared to the second period associated with transmitting the BCH using the FDD frame structure. And may be shortened. In another aspect, CRC masking may be included in the BCH to indicate a narrowband TDD frame structure. In another aspect, at least one of a period associated with transmitting the BCH, a temporal position associated with transmitting the BCH, or a frequency position associated with transmitting the BCH is narrow. It may relate to a narrowband TDD frame structure determined for band communication. In another aspect, the BCH is a first bit indicating a narrowband TDD frame structure determined for narrowband communication, a second bit indicating a FDD frame structure determined for narrowband communication, or SIB. It may include at least one of information indicating a resource block position or a subframe position associated with. In some other aspects, an apparatus 1902/1902′ for wireless communication may include means for transmitting a system information block using a determined narrowband TDD frame structure for narrowband communication. Good. In an aspect, SIBs may be transmitted using the same resource blocks used to transmit one or more of PSS, SSS, or BCH. In another aspect, the SIB may be transmitted using a resource block that is different from the resource block used to transmit one or more of PSS, SSS, or BCH. In a further aspect, at least one of the resource blocks or subframes used to transmit the SIB may be associated with a narrowband TDD frame structure determined for narrowband communication. In some other aspects, an apparatus 1902/1902′ for wireless communication may include means for transmitting information indicating additional subframes used to transmit NRS. In one aspect, the information may include broadcast signaling. In some other aspects, an apparatus 1902/1902′ for wireless communication may include means for transmitting an NRS using the narrowband TDD frame structure determined for narrowband communication. In an aspect, NRS may be transmitted using subframes that are also used to transmit SIB and BCH. In another aspect, the NRS may be transmitted using a resource block that is different than the resource block used to transmit at least one of the PSS or SSS. In another aspect, the same subframes used to transmit NRS, SIB, and BCH may not depend on the narrowband TDD frame structure determined for narrowband communication. In a further aspect, the same subframes used to transmit NRS, SIB, and BCH may depend on the narrowband TDD frame structure determined for narrowband communication. In another aspect, the density of NRS transmitted using the narrowband TDD frame structure may be increased compared to the density of NRS transmitted using the narrowband FDD frame structure. In yet another aspect, the NRS is transmitted in the same subframe used to transmit the CRS. In a still further aspect, the NRS may be transmitted in the downlink portion of the special subframe in the narrowband TDD frame structure determined for narrowband communication. In one aspect, the symbols used to transmit the NRS in the downlink portion of the special subframe are the same as the symbols used to transmit the NRS in the downlink subframe in the narrowband TDD frame structure. It may be. In another aspect, any NRS symbol present in the uplink part of the special subframe may be punctured. In a further aspect, the symbols used to transmit the NRS in the downlink portion of the special subframe are different than the symbols used to transmit the NRS in the downlink subframe in the narrowband TDD frame structure. Good. In some aspects, the NRS may be transmitted on a carrier that includes the SIB or BCH. In some other configurations, the minimal set of subframes includes subframes used to transmit SIBs and BCHs. In some other aspects, the minimum set of subframes used to transmit the NRS may not depend on the narrowband TDD frame structure determined for narrowband communication. In some other configurations, the minimum set of subframes may be constrained to subframes that are downlink subframes or special subframes in all supported TDD frame structures for narrowband communication. .. In some aspects, the minimum set of subframes used to transmit the NRS may depend on the narrowband TDD frame structure determined for narrowband communication. In some other aspects, the NRS may be transmitted in the symbols and resource elements used to transmit the CRS. In some other aspects, the symbols used to transmit the NRS may be determined based on the number of downlink symbols in the special subframe configuration. The above-mentioned means may be one or more of the above-mentioned components of the processing system 2014 of the device 1902 and/or the device 1902' configured to perform the functions enumerated by the above-mentioned means. As described above, processing system 2014 may include TX processor 316, RX processor 370, and controller/processor 375. Thus, in one configuration, the above-described means may be TX processor 316, RX processor 370, and controller/processor 375 configured to perform the functions recited by the above-described means.

FIG. 21 is a diagram illustrating a data flow 2100 that may be used for narrowband communication, according to some aspects of the present disclosure. For example, data flow 2100 may be performed by base station 2104 and/or UE 2106. Base station 2104 corresponds to, for example, base station 102, 180, 504, eNB310, device 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'. Sometimes. The UE 2106 may correspond to the UE 104, 350, 506, 1150, 1350, 1550, 1750, 1950, 2350, for example. Additionally, base station 2104 and UE 2106 may be configured to communicate using narrowband communication 2109 (eg, NB-IoT and/or eMTC). For example, the UE 2106 may be a NB-IoT device and/or an eMTC device.

In one aspect, the base station 2104 may determine a narrowband TDD frame structure for narrowband communication (2101). The narrowband TDD frame structure may include one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, and/or a set of flexible subframes. For example, base station 2104 determines that the narrowband TDD frame structure is one of configurations 0, 1, 2, 3, 4, 5, 6, l, or o from table 410 of FIG. You may (2101).

In another aspect, the base station 2104 may send a bitmap 2103 associated with the narrowband TDD frame structure to the UE 2106. Bitmap 2103 may indicate a set of downlink subframes, a set of uplink subframes, a set of special subframes, and/or a set of flexible subframes within the determined narrowband TDD frame structure.

In an aspect, a single indicating a set of downlink subframes, a set of uplink subframes, a set of special subframes, and/or a set of flexible subframes when the base station 2104 is operating in in-band mode. Of the bitmap 2103 of may be transmitted to the UE 2106. Instead, when the base station 2104 is operating in standalone mode, a first bitmap 2103 showing a set of downlink subframes, a second bitmap 2103 showing a set of uplink subframes, a special subframe The third bitmap 2103 indicating the set and/or the fourth bitmap 2103 indicating the set of flexible subframes may be separately transmitted to the UE 2106.

In some aspects, the first length of the bitmap 2103 associated with the determined narrowband TDD frame structure may be greater than the second length of a different bitmap associated with the narrowband FDD frame structure. For example, a single bitmap of length N (e.g. N=60) is used to indicate one or more of downlink and/or uplink subframes in a narrowband FDD frame structure. May be. In some aspects, the length N of the bitmap 2103 used to indicate the available downlink subframes, uplink subframes, special subframes, and/or flexible subframes in the narrowband TDD frame structure is , May be larger than the bitmap used to indicate the narrowband FDD frame structure (eg, N=80). The length of the narrowband TDD frame structure bitmap may be greater than the narrowband FDD frame structure bitmap, which used the narrowband FDD frame structure (e.g., uplink subframe and/or downlink subframe). More types of subframes available for allocation using narrowband TDD frame structure (eg, uplink subframes, downlink subframes, special subframes, and/or flexible subframes) Because there are things.

When the base station 2104 allocates one or more flexible subframes for the NPDCCH and/or NPDSCH, the UE 2106 may decode the NRS and NPDCCH and/or NPDSCH transmitted on the allocated flexible subframes. Good. When base station 2104 allocates one or more flexible subframes for NPUCCH and/or NPUSCH, UE 2106 may use the allocated flexible subframes to transmit NPUCCH and/or NPUSCH. .. The UE 2106 may ignore the flexible subframe when the flexible subframe is not allocated for NPDCCH, NPDSCH, NPUCCH, or NPUSCH. For example, UE 2106 may not perform NRS detection on flexible subframes when flexible subframes are not allocated due to NPDCCH, NPDSCH, NPUCCH, or NPUSCH.

FIG. 22 is a flowchart 2200 of a method of wireless communication. The method may include a base station (e.g., base station 102, 180, 504, 2104, eNB310, device 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'. ). In FIG. 22, the optional actions are indicated by dotted lines.

At 2202, the base station may determine a narrowband TDD frame structure for narrowband communication. In an aspect, the narrowband TDD frame structure may include one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes. In one aspect, flexible subframes may be configurable by the base station as either downlink subframes or uplink subframes. For example, referring to FIG. 21, a base station 2104 includes one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, and/or a set of flexible subframes. , A narrowband TDD frame structure for narrowband communication may be determined (2101). For example, the base station 2104 determines that the narrowband TDD frame structure is any of the configurations 0, 1, 2, 3, 4, 5, 6, l, or o from table 410 of FIG. Good (2101).

At 2204, the base station may send a bitmap associated with the narrowband TDD frame structure to the UE. In one aspect, the bitmap may indicate one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes. In another aspect, the first length of the bitmap associated with the narrowband TDD frame structure may be greater than the second length of a different bitmap associated with the narrowband FDD frame structure. For example, referring to FIG. 21, base station 2104 may send a bitmap 2103 associated with a narrowband TDD frame structure to UE 2106. Bitmap 2103 may indicate a set of downlink subframes, a set of uplink subframes, a set of special subframes, and/or a set of flexible subframes within the determined narrowband TDD frame structure.

At 2206, the base station sends a single bitmap indicating one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes. Accordingly, the bitmap associated with the narrowband TDD frame structure may be transmitted to the UE. For example, referring to FIG. 21, when the base station 2104 is operating in in-band mode, a set of downlink subframes, a set of uplink subframes, a set of special subframes, and/or a set of flexible subframes. May be transmitted to UE 2106.

At 2208, the base station may send the bitmap associated with the narrowband TDD frame structure to the UE by sending first information indicating a set of downlink subframes. For example, referring to FIG. 21, when the base station 2104 is operating in standalone mode, the first bitmap 2103 indicating the set of downlink subframes may be separately transmitted to the UE 2106.

At 2210, the base station may send a bitmap associated with the narrowband TDD frame structure to the UE by sending second information indicating a set of uplink subframes. For example, referring to FIG. 21, when the base station 2104 is operating in standalone mode, the second bitmap 2103 indicating the set of uplink subframes may be separately transmitted to the UE 2106.

At 2212, the base station may send a bitmap associated with the narrowband TDD frame structure to the UE by sending third information indicating a set of special subframes. For example, referring to FIG. 21, when the base station 2104 is operating in standalone mode, the third bitmap 2103 indicating the set of special subframes may be separately transmitted to the UE 2106.

At 2214, the base station may send a bitmap associated with the narrowband TDD frame structure to the UE by sending fourth information indicating the set of flexible subframes. For example, referring to FIG. 21, when the base station 2104 is operating in standalone mode, the fourth bitmap 2103 indicating the set of flexible subframes may be separately transmitted to the UE 2106.

FIG. 23 is a conceptual dataflow diagram 2300 illustrating dataflow between different means/components in an exemplary apparatus 2302. The device is a base station (e.g., base station 102, 180) that is in narrow band communication (e.g., NB-IoT communication or eMTC) with a UE 2350 (e.g., UE 104, 350, 506, 1150, 1350, 1550, 1950, 2104). , 310, 504, 2104, devices 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302'). The device may include a receiving component 2304, a determining component 2306, and a transmitting component 2308.

The determining component 2306 may be configured to determine a narrowband TDD frame structure for narrowband communication. In an aspect, the narrowband TDD frame structure may include one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes. In one aspect, flexible subframes may be configurable by the base station as either downlink subframes or uplink subframes. The decision component 2306 is information associated with a narrowband TDD frame structure with one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes. A signal 2301 including a may be transmitted to the transmitting component 2308.

The sending component 2308 may send the bitmap 2303 associated with the narrowband TDD frame structure to the UE 2350. In one aspect, the bitmap may indicate one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes. In another aspect, the first length of the bitmap associated with the narrowband TDD frame structure may be longer than the second length of a different bitmap associated with the narrowband FDD frame structure. In some aspects, the sending component 2308 is configured to send the bitmap 2303 associated with the narrowband TDD frame structure to the UE 2350 by sending first information indicating a set of downlink subframes. May be. In some other aspects, the transmitting component 2308 causes the bitmap 2303 associated with the narrowband TDD frame structure to be transmitted to the UE 2350 by transmitting second information indicating a set of uplink subframes. It may be configured. In some other aspects, the sending component 2308 is configured to send the bitmap 2303 associated with the narrowband TDD frame structure to the UE 2350 by sending a third information indicating a set of special subframes. May be done. In some other aspects, the sending component 2308 is configured to send the bitmap 2303 associated with the narrowband TDD frame structure to the UE 2350 by sending a fourth information indicating a set of flexible subframes. May be done.

The receiving component 2304 and/or the transmitting component 2308 may be configured to communicate (2303, 2305) with the UE 1750 using a narrowband TDD frame structure determined for narrowband communication. For example, the receiving component 2304 may be configured to receive the narrowband uplink transmission 2305 from the UE 2350. Transmission component 2308 may be configured to send one or more narrowband downlink transmissions 2303 to UE 2350.

The apparatus may include additional components that implement each of the blocks of the algorithm in the above flowchart of FIG. As such, each block in the above-described flowchart of FIG. 22 may be performed by one component and an apparatus may include one or more of those components. A component is one or more hardware components specifically configured to perform the described process/algorithm, or by a processor configured to perform the described process/algorithm. It may be implemented, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

FIG. 24 is a diagram 2400 illustrating an example hardware implementation of a device 2302′ utilizing a processing system 2414. Processing system 2414 may be implemented with a bus architecture represented generally by bus 2424. Bus 2424 may include any number of interconnected buses and bridges depending on the particular application of processing system 2414 and the overall design constraints. Bus 2424 couples together various circuits including one or more processor and/or hardware components represented by processor 2404, components 2304, 2306, 2308, and computer readable media/memory 2406. Bus 2424 may also connect various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and are therefore These circuits will not be described further.

The processing system 2414 may be coupled to the transceiver 2410. Transceiver 2410 is coupled to one or more antennas 2420. Transceiver 2410 provides a means for communicating with a variety of other devices via a transmission medium. Transceiver 2410 receives signals from one or more antennas 2420, extracts information from the received signals, and provides the extracted information to processing system 2414, particularly receiving component 2304. In addition, the transceiver 2410 receives information from the processing system 2414, specifically the transmitting component 2308, and based on the received information, generates a signal to be applied to one or more antennas 2420. Processing system 2414 includes a processor 2404 coupled to a computer-readable medium/memory 2406. Processor 2404 is responsible for general processing, including execution of software stored in computer-readable media/memory 2406. The software, when executed by the processor 2404, causes the processing system 2414 to perform the various functions described above for any particular device. Computer readable media/memory 2406 may also be used to store data manipulated by processor 2404 when executing software. Processing system 2414 further includes at least one of components 2304, 2306, 2308. These components operate within the processor 2404 and reside on or are stored in a computer-readable medium/memory 2406, one or more hardware components coupled to the processor 2404, or the like. May be some combination. Processing system 2414 may be a component of base station 310 and may include memory 376 and/or at least one of TX processor 316, RX processor 370, and controller/processor 375.

In some aspects an apparatus 2302/2302′ for wireless communication may include means for determining a narrowband TDD frame structure for narrowband communication. In an aspect, the narrowband TDD frame structure may include one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes. In one aspect, flexible subframes may be configurable by the base station as either downlink subframes or uplink subframes. In some other aspects, an apparatus 2302/2302′ for wireless communication may include means for transmitting a bitmap associated with a narrowband TDD frame structure to a UE. In one aspect, the bitmap may indicate one or more of a set of downlink subframes, a set of uplink subframes, a set of special subframes, or a set of flexible subframes. In another aspect, the first length of the bitmap associated with the narrowband TDD frame structure may be longer than the second length of a different bitmap associated with the narrowband FDD frame structure. In some aspects, the means for transmitting a bitmap associated with a narrowband TDD frame structure to a UE includes a downlink subframe set, an uplink subframe set, a special subframe set, or a flexible subframe. May be configured to send a single bitmap indicating one or more of the set of In some aspects, the means for transmitting the bitmap associated with the narrowband TDD frame structure to the UE may be configured to transmit the first information indicative of the set of downlink subframes. In some aspects, the means for transmitting the bitmap associated with the narrowband TDD frame structure to the UE may be configured to transmit second information indicative of the set of uplink subframes. In some aspects, the means for transmitting the bitmap associated with the narrowband TDD frame structure to the UE may be configured to transmit third information indicating a set of special subframes. In some aspects, the means for transmitting the bitmap associated with the narrowband TDD frame structure to the UE may be configured to transmit fourth information indicative of the set of flexible subframes. The above-mentioned means may be one or more of the above-mentioned components of the processing system 2414 of the device 2302 and/or the device 2302′ configured to perform the functions enumerated by the above-mentioned means. As described above, processing system 2414 may include TX processor 316, RX processor 370, and controller/processor 375. Thus, in one configuration, the means described above may be TX processor 316, RX processor 370, and controller/processor 375 configured to perform the functions recited by the means described above.

FIG. 25 is a flowchart 2500 of a method of wireless communication. The method is performed by a base station (e.g., base station 102, 180, 504, eNB310, device 1102/1102', 1302/1302', 1502/1502', 1702/1702', 1902/1902', 2302/2302'). It may be executed. In FIG. 25, the optional actions are indicated by dotted lines.

At 2502, the base station may determine a narrowband TDD frame structure for narrowband communication from a group of narrowband TDD frame structures. For example, referring to FIGS.5B-5D, base station 504 may select a narrowband TDD frame structure for narrowband communication 509 from a group of narrowband TDD frame structures (e.g., configurations listed in table 410 of FIG. 4). May be determined (515).

At 2504, the base station determines a set of narrowband carriers and a set of narrowband carriers based at least in part on a downlink subframe and a set of two or more special subframes on which the NRS is to be transmitted. A minimum set of subframes may be determined. In some aspects, the minimum set of subframes used to transmit the NRS may not depend on the narrowband TDD frame structure determined for narrowband communication. In some other aspects, the minimal set of subframes is constrained to subframes that are downlink subframes or special subframes in all supported TDD frame structures for narrowband communication. Good. In some other aspects, the minimum set of subframes used to transmit the NRS may depend on the narrowband TDD frame structure determined for narrowband communication. For example, referring to FIGS.5B-5D, base station 504 determines that NRS 541 is to transmit on a set of narrowband carriers and a minimal set of subframes (e.g., common subframes described above). ) May be determined. For example, when the narrowband TDD frame structure is determined from one of the configurations 0, 1, 2, 3, 4, 5, 6, and m, the NRS 541 is one of subframe 0 or subframe 5 , Since subframes 0 and 5 are common downlink subframes in each configuration in the group. Further, the NRS 541 may be transmitted in subframe 1 or subframe 6, which means that subframes 1 and 6 are special subframes (e.g., including downlink resources) or configurations 0, 1, 2, 3, 4 , 5, 6, and m are downlink subframes. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, the NRS 541 is subframe 0, subframe 5, or subframe 9 May be transmitted in one of the following, because subframes 0, 5, and 9 are common downlink subframes in each of configurations 1, 2, 3, 4, 5, and 6. is there. Instead, the base station 504 does not depend on the NRS541
May be sent. For example, the NPBCH 535 transmitted by the base station 504 sends the downlink subframe containing the NRS 541 to the UE 506 when the downlink subframe used to transmit the NRS 541 does not depend on the determined narrowband TDD frame structure. May be used to indicate. In some aspects bitmap 539 may be included in NPBCH 535.

At 2506, the base station may send information indicating additional subframes used to send the NRS. In one aspect, the information may include broadcast signaling. For example, referring to FIGS. 5B-5D, base station 504 may send NRS 541 in a downlink subframe that is independent of the determined narrowband TDD frame structure. For example, the NPBCH 535 (e.g., broadcast signaling) transmitted by the base station 504 may include the NRS 541 when the downlink subframe used to transmit the NRS 541 does not depend on the determined narrowband TDD frame structure. It may be used to indicate the link subframe to the UE 506.

At 2508, the base station may transmit the NRS using the narrowband TDD frame structure determined for narrowband communication. In an aspect, NRS may be transmitted using subframes that are also used to transmit SIB and BCH. In another aspect, the NRS may be transmitted using a resource block that is different than the resource block used to transmit at least one of the PSS or SSS. In another aspect, the same subframes used to transmit NRS, SIB, and BCH may not depend on the narrowband TDD frame structure determined for narrowband communication. In a further aspect, the same subframes used to transmit NRS, SIB, and BCH may depend on the narrowband TDD frame structure determined for narrowband communication. In another aspect, the density of NRS transmitted using the narrowband TDD frame structure may be increased compared to the density of NRS transmitted using the narrowband FDD frame structure. In yet another aspect, the NRS is transmitted in the symbols and resource elements used to transmit the CRS. In a still further aspect, the NRS may be transmitted in the downlink portion of the special subframe in the narrowband TDD frame structure determined for narrowband communication. In one aspect, the symbols used to transmit the NRS in the downlink portion of the special subframe are the same as the symbols used to transmit the NRS in the downlink subframe in the narrowband TDD frame structure. It may be. In another aspect, any NRS symbol present in the uplink part of the special subframe may be punctured. In a further aspect, the symbols used to transmit the NRS in the downlink portion of the special subframe are different than the symbols used to transmit the NRS in the downlink subframe in the narrowband TDD frame structure. Good. In some aspects, the symbols used to transmit the NRS are determined based on the number of downlink symbols in the special subframe structure. For example, referring to FIGS. 5B-5D, base station 504 may transmit NRS 541 using a narrowband TDD frame structure determined for narrowband communication 509. For example, base station 504
The NRS may be transmitted using subframes that are also used to transmit SIB537 and/or NPBCH535. In addition, NRS 541 may be transmitted using a different RB than the RB used to transmit NPSS 521 and/or NSSS 529. In some aspects, base station 504 may transmit NRS 541 using one of the common subframes described above. For example, when the narrowband TDD frame structure is determined from one of the configurations 0, 1, 2, 3, 4, 5, 6, and m, the NRS 541 is one of subframe 0 or subframe 5 , Since subframes 0 and 5 are common downlink subframes in each configuration in the group. Further, the NRS 541 may be transmitted in subframe 1 or subframe 6, which means that subframes 1 and 6 are special subframes (e.g., including downlink resources) or downlink subframes in each configuration in the group. This is because it is a frame. In another example, when the narrowband TDD frame structure is determined from one of configurations 1, 2, 3, 4, 5, and 6, the NRS 541 is subframe 0, subframe 5, or subframe 9 May be transmitted in one of the subframes 0, 5, and 9 because they are common downlink subframes in each configuration in the group. The NRS 541 may be transmitted in the DwPTS portion of the special subframe (eg, see FIG. 4) in the determined narrowband TDD frame structure and in the downlink subframe. In one aspect, the same symbols in the DwPTS portion of the special subframe and the downlink subframe may be used to transmit NRS 541. When the NRS 541 is transmitted in the DwPTS of the special subframe, the UpPTS part of the special subframe may be punctured. In some aspects, the density of NRS 541 transmitted using a narrowband TDD frame structure may be higher than the density of NRS transmitted using a narrowband FDD frame structure. In other configurations, NRS 541 may be transmitted in the symbols and resource elements that base station 504 uses to transmit the CRS.

It is to be understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is exemplary of exemplary approaches. It should be appreciated that the particular order or hierarchy of blocks in the process/flowchart may be rearranged based on design preferences. Moreover, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The above description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications of these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims should not be limited to the embodiments set forth herein, but should be given the full range of claims consistent with the wording of the claims, and references to elements in the singular, Unless specified otherwise, means "one or more," not "unique." The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Unless otherwise stated, the term "some" refers to one or more. "At least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C", "A, B , And C, and ``a, B, C, or any combination thereof'' includes any combination of A, B, and/or C, and a plurality of A , Multiple Bs, or multiple Cs. Specifically, "at least one of A, B, or C", "one or more of A, B, or C", "at least one of A, B, and C". , "One or more of A, B, and C", and "A, B, C, or any combination thereof" are A only, B only, C only, A and B, It may be A and C, B and C, or A and B and C, and any such combination may include one or more members of A, B, or C. All structural and functional equivalents to elements of various aspects described throughout this disclosure that are known to, or will be known to, those of ordinary skill in the art are expressly incorporated herein by reference. , Are intended to be covered by the claims. Furthermore, nothing disclosed herein is provided to the public regardless of whether such disclosure is explicitly recited in the claims. The words "module,""mechanism,""element,""device," etc. may not be substitutes for the word "means." Therefore, no claim element should be construed as a means-plus-function unless the element is explicitly recited using the phrase "means for."

102 base stations
104 UE
110 geographical coverage area
120 communication link
132 backhaul link
134 Backhaul link
150 AP
152 STA
154 Communication link
160 EPC
162 MME
164 Other MMEs
166 Serving gateway
168 MBMS GW
170 BM-SC
172 PDN Gateway
174 HSS
176 IP Service
180 gNB
184 Beam forming
192 D2D communication link
198 Narrowband TDD frame structure for narrowband communication
310 eNB
316 TX Processor
318 transmitter
320 receiver
350 UE
352 transmitter
354 receiver
356 RX processor
358 channel estimator
359 controller/processor
360 memory
368 TX Processor
370 RX Processor
374 channel estimator
375 controller/processor
376 memory
400 narrow band TDD frame structure
410 table
412 Narrowband TDD frame structure
414 Narrowband TDD frame structure
416 Narrowband TDD frame structure
504 Base station
505 NSSS
506 UE
507 SIB
509 Narrowband communication
510 data flow
521 NPSS
527 Exploration
529 NSSS
535 NPBCH
537 SIB
539 bitmap
541 NRS
1101 signal
1102 equipment
1103 SIB
1104 Receiving component
1105 NB UL transmission
1106 Decision component
1108 Send component
1150 UE
1204 processor
1206 Computer-readable media/memory
1210 transceiver
1214 processing system
1220 antenna
1224 bus
1301 signal
1302 equipment
1303 Information
1304 Receiving component
1305 NB UL transmission
1306 Decision component
1308 Send component
1350 UE
1404 processor
1406 Computer-readable media/memory
1410 transceiver
1414 processing system
1420 antenna
1424 bus
1501 signal
1502 equipment
1503 PSS
1504 Receive component
1505 NB UL transmission
1506 Decision component
1508 Send component
1550 equipment
1604 processor
1606 Computer-readable media/memory
1610 transceiver
1614 processing system
1620 antenna
1624 bus
1701 signal
1702 equipment
1703 PSS
1704 Receiving component
1705 NB UL transmission
1706 Decision component
1708 Send component
1804 processor
1806 Computer-readable media/memory
1810 transceiver
1814 processing system
1820 antenna
1824 bus
1901 signal
1902 device
1903 BCH
1904 Receiving component
1905 NB UL transmission
1906 Decision component
1908 Send component
1950 UE
2004 processor
2006 Computer-readable media/memory
2010 transceiver
2014 processing system
2020 antenna
2024 bus
2103 bitmap
2104 Base station
2106 UE
2109 Narrowband communication
2301 Signal
2302 equipment
2303 bitmap
2304 Receiving component
2305 NB UL transmission
2306 Decision component
2308 Send component
2404 processor
2406 Computer-readable media/memory
2410 transceiver
2414 processing system
2420 antenna
2424 bus

Claims (56)

A method of wireless communication for a base station, comprising:
Determining a TDD frame structure for narrow band communication from a group of time division duplex (TDD) frame structures, the TDD frame structure including a downlink subframe and a set of two or more special subframes. , Step,
Narrowband reference signal (NRS) is based on the set of downlink subframes and at least two special sub-frame to be transmitted on the sub on the set of the set and the narrow-band carrier of the narrow-band carrier Determining a minimum set of frames, said minimum set of subframes being downlink subframes or special subframes in all supported TDD frame structures for said narrowband communication Steps constrained to subframes,
Transmitting the NRS using the TDD frame structure determined for the narrowband communication. The NRS is transmitted on a carrier that includes a system information block (SIB) or a broadcast channel (BCH), the minimum set of subframes includes subframes used to transmit the SIB and the BCH, The method of claim 1. The method of claim 2, wherein the minimal set of subframes used to transmit the NRS is independent of the TDD frame structure determined for the narrowband communication. The method of claim 2, wherein the minimal set of subframes used to transmit the NRS depends on the TDD frame structure determined for the narrowband communication. The method of claim 1, further comprising transmitting information indicating additional subframes used to transmit the NRS. The method of claim 5, wherein the information comprises broadcast signaling. The NRS transmits using a first resource block that is different from a second resource block used to transmit at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS) The method of claim 1, wherein the method is performed. The density of the NRS transmitted using the TDD frame structure is increased compared to the density of different NRS transmitted using a frequency division duplex (FDD) frame structure for narrowband communication, The method of claim 1. 9. The method of claim 8, wherein the NRS is transmitted in symbols and resource elements used to transmit cell-specific reference signals (CRS). The method of claim 1, wherein the NRS is transmitted in a downlink portion of a special subframe in the TDD frame structure determined for narrowband communication. The symbol used to transmit the NRS in the downlink portion of the special subframe is also the symbol used to transmit the NRS in the downlink subframe in the TDD frame structure. The method according to item 10. 11. The method according to claim 10, wherein every NRS symbol present in the uplink part of the special subframe is punctured. The first symbol used to transmit the NRS in the downlink portion of the special subframe is the second symbol used to transmit the NRS in the downlink subframe in the TDD frame structure. 11. The method of claim 10, wherein the method is different than the symbol of. 11. The method of claim 10, wherein the symbols used to transmit the NRS are determined based on the number of downlink symbols in a special subframe structure. A device for wireless communication for a base station, comprising:
A means for determining a TDD frame structure for narrowband communication from a group of time division duplex (TDD) frame structures, said TDD frame structure being a downlink subframe and a set of two or more special subframes. Means, including,
Narrowband reference signal (NRS) is based on the set of downlink subframes and at least two special sub-frame to be transmitted on the sub on the set of the set and the narrow-band carrier of the narrow-band carrier A means for determining a minimum set of frames, wherein said minimum set of subframes is a downlink subframe or a special subframe in all supported TDD frame structures for said narrowband communication. Means for determining, constrained to a subframe which is
Means for transmitting the NRS using the TDD frame structure determined for the narrowband communication. The NRS is transmitted on a carrier that includes a system information block (SIB) or a broadcast channel (BCH), the minimum set of subframes includes subframes used to transmit the SIB and the BCH, The device according to claim 15. 17. The apparatus of claim 16, wherein the minimal set of subframes used to transmit the NRS is independent of the TDD frame structure determined for the narrowband communication. 17. The apparatus of claim 16, wherein the minimal set of subframes used to transmit the NRS depends on the TDD frame structure determined for the narrowband communication. 16. The apparatus of claim 15, further comprising means for transmitting information indicating additional subframes used to transmit the NRS. 20. The apparatus of claim 19, wherein the information comprises broadcast signaling. The NRS transmits using a first resource block that is different from a second resource block used to transmit at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS) 17. The device of claim 16, which is: The density of the NRS transmitted using the TDD frame structure is increased compared to the density of different NRS transmitted using a frequency division duplex (FDD) frame structure for narrowband communication, The apparatus according to claim 16. 23. The apparatus of claim 22, wherein the NRS is transmitted in symbols and resource elements used to transmit cell-specific reference signals (CRS). 17. The apparatus of claim 16, wherein the NRS is transmitted in a downlink part of a special subframe in the TDD frame structure determined for narrowband communication. The symbol used to transmit the NRS in the downlink portion of the special subframe is also the symbol used to transmit the NRS in the downlink subframe in the TDD frame structure. The apparatus according to Item 24. 25. The apparatus of claim 24, wherein every NRS symbol present in the uplink part of the special subframe is punctured. The first symbol used to transmit the NRS in the downlink portion of the special subframe is the second symbol used to transmit the NRS in the downlink subframe in the TDD frame structure. 25. The device of claim 24, which is different than the symbol of. 25. The apparatus of claim 24, wherein the symbols used to transmit the NRS are determined based on the number of downlink symbols in special subframe configuration. A device for wireless communication for a base station, comprising:
Memory and
At least one processor coupled to the memory, the processor comprising:
Determining a TDD frame structure for narrowband communication from a group of time division duplex (TDD) frame structures, the TDD frame structure including a downlink subframe and a set of two or more special subframes. , To make a decision,
Narrowband reference signal (NRS) is based on the set of downlink subframes and at least two special sub-frame to be transmitted on the sub on the set of the set and the narrow-band carrier of the narrow-band carrier Determining a minimal set of frames, said minimal set of subframes being downlink subframes or special subframes in all supported TDD frame structures for said narrowband communication Deciding, constrained by subframes,
Transmitting the NRS using the TDD frame structure determined for the narrowband communication. The NRS is transmitted on a carrier that includes a system information block (SIB) or a broadcast channel (BCH), the minimum set of subframes includes subframes used to transmit the SIB and the BCH, The device of claim 29. 31. The apparatus of claim 30, wherein the minimal set of subframes used to transmit the NRS is independent of the TDD frame structure determined for the narrowband communication. 31. The apparatus of claim 30, wherein the minimal set of subframes used to transmit the NRS depends on the TDD frame structure determined for the narrowband communication. The at least one processor further
30. The apparatus of claim 29, configured to transmit information indicating additional subframes used to transmit the NRS. 34. The apparatus of claim 33, wherein the information comprises broadcast signaling. The NRS transmits using a first resource block that is different from a second resource block used to transmit at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS) 30. The device of claim 29, which is: The density of the NRS transmitted using the TDD frame structure is increased compared to the density of different NRS transmitted using a frequency division duplex (FDD) frame structure for narrowband communication, The device of claim 29. 37. The apparatus of claim 36, wherein the NRS is transmitted in symbols and resource elements used to transmit cell-specific reference signals (CRS). 30. The apparatus of claim 29, wherein the NRS is transmitted in a downlink portion of a special subframe in the TDD frame structure determined for narrowband communication. The symbol used to transmit the NRS in the downlink portion of the special subframe is also the symbol used to transmit the NRS in the downlink subframe in the TDD frame structure. The apparatus according to Item 38. 39. The apparatus of claim 38, wherein every NRS symbol present in the uplink portion of the special subframe is punctured. The first symbol used to transmit the NRS in the downlink portion of the special subframe is the second symbol used to transmit the NRS in the downlink subframe in the TDD frame structure. 39. The device of claim 38, which is different than the symbol of. 39. The apparatus of claim 38, wherein the symbols used to transmit the NRS are determined based on the number of downlink symbols in a special subframe structure. A computer readable recording medium storing computer executable code for a base station, comprising:
Determining a TDD frame structure for narrowband communication from a group of time division duplex (TDD) frame structures, the TDD frame structure including a downlink subframe and a set of two or more special subframes. , To make a decision,
Narrowband reference signal (NRS) is based on the set of downlink subframes and at least two special sub-frame to be transmitted on the sub on the set of the set and the narrow-band carrier of the narrow-band carrier Determining a minimal set of frames, said minimal set of subframes being downlink subframes or special subframes in all supported TDD frame structures for said narrowband communication Deciding, constrained by subframes,
A computer-readable recording medium comprising code for transmitting the NRS using the TDD frame structure determined for the narrowband communication. The NRS is transmitted on a carrier that includes a system information block (SIB) or a broadcast channel (BCH), the minimum set of subframes includes subframes used to transmit the SIB and the BCH, The computer-readable recording medium according to claim 43. 45. The computer-readable recording medium of claim 44, wherein the minimal set of subframes used to transmit the NRS does not depend on the TDD frame structure determined for the narrowband communication. 45. The computer-readable recording medium of claim 44, wherein the minimal set of subframes used to transmit the NRS depends on the TDD frame structure determined for the narrowband communication. 44. The computer-readable recording medium of claim 43, further comprising code for transmitting information indicating additional subframes used to transmit the NRS. 48. The computer-readable recording medium of claim 47, wherein the information comprises broadcast signaling. The NRS transmits using a first resource block that is different from a second resource block used to transmit at least one of a primary synchronization signal (PSS) or a secondary synchronization signal (SSS) 44. The computer-readable recording medium according to claim 43, which is: The density of the NRS transmitted using the TDD frame structure is increased compared to the density of different NRS transmitted using a frequency division duplex (FDD) frame structure for narrowband communication, The computer-readable recording medium according to claim 43. 51. The computer-readable recording medium of claim 50, wherein the NRS is transmitted in symbols and resource elements used to transmit cell-specific reference signal (CRS). 44. The computer-readable recording medium of claim 43, wherein the NRS is transmitted in a downlink portion of a special subframe in the TDD frame structure determined for narrowband communication. The symbol used to transmit the NRS in the downlink portion of the special subframe is also the symbol used to transmit the NRS in the downlink subframe in the TDD frame structure. The computer-readable recording medium according to Item 52. 53. The computer readable recording medium of claim 52, wherein every NRS symbol present in the uplink part of the special subframe is punctured. The first symbol used to transmit the NRS in the downlink portion of the special subframe is the second symbol used to transmit the NRS in the downlink subframe in the TDD frame structure. 53. The computer-readable recording medium according to claim 52, which is different from the symbol of. 53. The computer-readable recording medium of claim 52, wherein the symbols used to transmit the NRS are determined based on the number of downlink symbols in a special subframe structure.